
Final Project
Group 6
John
Robert
Patrick
Evan
Matthew
Ali
(Excellent Project; Last
Names held for Privacy)
Table of Contents
·
Problem Statement
·
Executive Summary and Recommendations
·
Statistical Restatement
·
Report Notation
·
Descriptive Statistics and Residual Testing
·
Hypothesis Testing of the Variances
·
Hypothesis Testing of the Means
·
Simple Linear Regression Analysis
·
Cubic and Quadratic Regression Analysis
·
Multiple Regression Analysis
·
ANOVA
·
Two sample T-test of the means (small sample)
·
Best and Worst Case scenarios
·
Final Conclusions
·
Management Decision
Problem Statement
With the decrease in the recent economy
many corporations are finding it difficult to maintain a positive profit
margin. A poultry distribution company with two main distribution centers has
been deeply impacted by these recent events.
This company has two different distribution centers in the United
States. One plant is located in Oakland, California and the other is in Albany,
New York. The corporation’s management has made a decision to close one of the
distribution centers. Management has
hired us, group 6, to analyze which location should be kept open. Our group will analyze the major influences
of profit for each distribution center.
We were asked to look at data from the last nine years when performing
our analysis.
The
recommended decision is to close the California plant. It was determined that
the poultry prices were the best predictor of profits for New York and
California. Even in the worst case scenario, the plant in Albany, New York made
a significantly larger profit than in Oakland, California. The enclosed
statistical analyses of all of the contributing variables support this
decision.
Statistical Restatement
Our team has
found seven variables that are influential in determining the profits of each
distribution center. The six expense
variables that we are assessing are employment costs of truckers on the west
coast and east coast, the employment costs of poultry process employees on the
west coast and east coast, the price of diesel fuel on the east coast and west
coast. The price of the poultry is a
variable market price that is standard nationwide.
Through our preliminary assessment we have
also determined which statistical analysis will be needed in order to help the
managers make an informed decision on which distribution center to close. The data that has been collected over the
past nine years gives us monthly wages for truckers and poultry process
employees and weekly prices for diesel.
With such a large amount of data the analyses that we perform will be
geared towards large data sets.
The comparison of means and variances between
distribution centers will provide insight into the influence on the profits.
Regression will further provide insight as to the effect of the variables on
the profits.
It has been decided that profit for each
distribution center can be represented by the following general formula:
NY Profits (NYM) =
Poultry($)–Diesel($)–Labor($)– Drivers($)
CA Profits (CAM) =
Poultry($)–Diesel($)–Labor($)– Drivers($)
This
means that as the Diesel, Labor, and Driver prices increase, the profits will
decrease and vice-versa. The criteria
for each location is described as shown:
Albany, NY San Franscisco, CA
Diesel
Fuel Use (gal) 1200 750
Process
Employees 115 198
Weekly
Shipments (lbs) 1.2M 800K
The analysis is based on data collected
from the past 9 years. It is important
to determine how each of the variables (predictors) are related to the profits
(responses) for each distribution center.
A
summary of each analysis and its usefulness is outlined below:
1.
Descriptive Statistics and Residual Testing:
The descriptive statistics give us a general
impression of our data and the overall idea of what type of data sets we have
to work with. Most of our analyses have
been developed using the information calculated here.
2. Hypothesis Testing: Our hypothesis testing tests the means and
variance of the distribution center profits and datasets.
3. Simple Regression: For
each set of data determine the relationship between the dependent and
independent variables of the profit equation and forecast some future behavior
4.
Multiple
Regression: For each set of data
we perform multiple regression analyses between the independent and dependent
variables to evaluate the relationship
5.
One Way
ANOVA: Perform a one-way
analysis of variance (ANOVA) between specific variables and the distribution
center profit
WC GAS – West Coast Diesel Prices
EC GAS – East Coast Diesel Prices
PCA – California Poultry Process Workers Weekly Salary
PNY – New York Poultry Process Workers Weekly Salary
TCA – California Truckers Weekly Salary
TNY – New York Truckers Weekly Salary
PP – Poultry Prices
NYM – New York Profits
CAM – California Profits
The descriptive statistics of the data allows
for easier understanding. In addition,
it is important to analyze the residual plots of the data to be sure it is
random.


The
residual plot shown above is a healthy set of data. This data is homogenous and has a random scatter around
zero. We can conclude that this data is
random.

The
above graph shows a non homogeneous data set.


This
data is nearly non-homogeneous and is acceptable for this analysis.


This
data is nearly non-homogeneous and is acceptable for this analysis.
New
York Labor Prices (1993-2002)


This
data is non-homogeneous and acceptable for this analysis.
California Labor Prices
(1993-2002)


This data is non-homogeneous and acceptable
for this analysis.


This
data is non-homogeneous and acceptable for this analysis.


This
data is non-homogeneous and acceptable for this analysis.
Hypothesis Testing of the Variances
Test for Equal
Variances between the New York and California Profits
H0: s1
= s2
Level1
NYM
Level2
CAM
ConfLvl
95.0000
Bonferroni confidence intervals for standard
deviations

Lower
Sigma Upper N
Factor Levels
107680 123378
144186 120 NYM
71663 82110 95958
120 CAM
F-Test (normal distribution)
Test Statistic: 2.258
P-Value
: 0.000
Levene's Test (any continuous distribution)
Test Statistic: 15.736
P-Value
: 0.000
In both cases the
p-value is zero. With such a low
p-value there is very little chance of having the null hypothesis be true.
Decision : We cannot accept the H0
hypothesis, therefore we cannot conclude that the profit variances are equal
between the two states.
Test for Equal
Variances between the New York and California diesel prices
H0: H0: s1
= s2
Level1
EC DIESEL
Level2
WC DIESEL
ConfLvl
95.0000
Bonferroni confidence intervals for standard
deviations

Lower
Sigma Upper N
Factor Levels
0.135417
0.155158 0.181326 120
EC DIESEL
0.143413
0.164320 0.192033 120
WC DIESEL
F-Test (normal distribution)
Test Statistic: 0.892
P-Value
: 0.532
Levene's Test (any continuous distribution)
Test Statistic: 0.977
P-Value
: 0.324
n
this case the p-values are large and we can say that there is a significant
chance of the null hypothesis being correct.
Decision : We
cannot reject the H0 hypothesis, therefore we can conclude that the diesel
price variances are similar between the two states.
Test for Equal Variances between the New York
and California Truck Driver’s salaries
H0: s1
= s2
Level1
TNY
Level2
TCA
ConfLvl
95.0000
Bonferroni confidence intervals for standard
deviations

Lower
Sigma Upper N
Factor Levels
35.4808 40.6533 47.5097
120 TNY
31.7237 36.3485 42.4788
120 TCA
F-Test (normal distribution)
Test Statistic: 1.251
P-Value
: 0.224
Levene's Test (any continuous distribution)
Test Statistic: 0.513
P-Value
: 0.475
In
this case the p-values are large and we can say that there is a significant
chance of the null hypothesis being correct.
Decision : We cannot reject the H0
hypothesis, therefore we can conclude that the salary variances are equal
between the two states.
Test for Equal Variances between the New York
and California poultry worker salaries
H0: s1
= s2
Level1
PNY
Level2
PCA
ConfLvl
95.0000
Bonferroni confidence intervals for standard
deviations

Lower
Sigma Upper N
Factor Levels
38.8825 44.5510 52.0647
120 PNY
52.9050 60.6177 70.8410
120 PCA
F-Test (normal distribution)
Test Statistic: 0.540
P-Value
: 0.001
Levene's Test (any continuous distribution)
Test Statistic: 13.630
P-Value
: 0.000
In both cases the
p-value is practically zero. With such
a low p-value there is very little chance of having the null hypothesis be
true.
Decision : We cannot accept the H0
hypothesis, therefore we cannot conclude that the poultry worker salary
variances are equal between the two states.
Hypothesis Summary
For Variance Testing:
Test for Equal
Variances between the New York and California Profits: we cannot accept H0,
therefore we can’t assume equal variances.
Test for Equal Variances between the New York
and California diesel prices: we cannot reject H0, therefore we can
assume equal variances in this case
Test for Equal Variances between the New York
and California Truck Driver’s salaries: we cannot reject H0,
therefore we can assume equal variances.
Test for Equal Variances between the New York
and California poultry worker salaries: we cannot accept H0,
therefore we can’t assume equal variances.
Hypothesis
Testing of the means
Test of the means for the New York and
California diesel prices
Two
Tailed Test
One-Sample Z: East
Coast Diesel
Test of mu = 1.3142 vs mu not = 1.3142
The assumed sigma = 0.1552 EC Diesel Sigma
Variable N Mean StDev
SE Mean
EC DIESEL 120 1.1534 0.1552
0.0142
Variable 95.0% CI
Z P
EC DIESEL ( 1.1257, 1.1812)
-11.35 0.000
Since the P-Value is zero for both of the two
tailed tests the East Coast diesel versus the West Coast diesel prices we can
conclude that the means are not equal.
Reject the null.
One Tailed Tests
One-Sample Z: East
Coast Diesel
This test shows that the mean price of east coast diesel is less than
west coast diesel with 100% probability.
Test of mu = 1.3142 vs mu > 1.3142
The assumed sigma = 0.1552
Variable N Mean StDev
SE Mean
EC DIESEL 120 1.1534 0.1552
0.0142
Variable
95.0% Lower Bound Z P
EC DIESEL 1.1301
-11.35 1.000
One-Sample Z: East
Coast Diesel
This test displays that we can accept H1 that the east coast diesel price
is not equal to the west coast diesel price because the p value small.
Test of mu = 1.3142 vs mu < 1.3142
The assumed sigma = 0.1552
Variable N Mean StDev
SE Mean
EC DIESEL 120 1.1534 0.1552
0.0142
Variable
95.0% Upper Bound Z P
EC DIESEL 1.1767
-11.35 0.000
Test of the means for the New York and
California Truckers Salaries.
Two
Tailed Tests
The following two 1 sample z tests comparing the means of the trucker
weekly salaries result in p values that are less that alpha (alpha=0.05).
One-Sample Z:
Truckers NY
Test of mu = 598.54 vs mu not = 598.54
The assumed sigma = 40.65 NY Sigma
Variable N Mean StDev
SE Mean
TNY 120
590.40 40.65 3.71
Variable 95.0% CI
Z P
TNY
( 583.13, 597.67)
-2.19 0.028
Test of the means for the New York and
California Process Workers salaries
Two Tailed Test
One-Sample Z:
Process Workers NY
A one sample z
test was performed to check if the process worker means were equal. The p value
suggests that the mean are in fact not equal.
Test of mu = 701.92 vs mu not = 701.92
The assumed sigma = 44.55 NY Sigma
Variable N Mean StDev
SE Mean
PNY 120
573.81 44.55 4.07
Variable 95.0% CI
Z P
PNY
( 565.84, 581.78)
-31.50 0.000
One Tailed Tests
One-Sample Z:
Process Workers NY
These two one tailed z tests were performed to determine whether or not
the mean weekly salaries of the New York process workers was higher than the
California process workers.
Test of mu = 701.92 vs mu > 701.92
The assumed sigma = 44.55
Variable N Mean StDev
SE Mean
PNY 120
573.81 44.55 4.07
Variable
95.0% Lower Bound Z P
PNY 567.12
-31.50 1.000
One-Sample Z:
Process Workers NY
Test of mu = 701.92 vs mu < 701.92
The assumed sigma = 44.55
Variable N Mean StDev
SE Mean
PNY 120
573.81 44.55 4.07
Variable
95.0% Upper Bound Z P
PNY 580.50
-31.50 0.000
The
result of this series of hypothesis tests shows that the weekly mean salary of
New York process workers was less than the process workers in California.
Test of the means for the New York and
California profits
Two Tailed Test
One-Sample Z: New
York Profits
This test below was performed to determine if the means of the New York
and California profits were equal. From this test is displayed that the mean
profits from New York and California are not equal.
Test of mu = 889739 vs mu not = 889739
The assumed sigma = 123378 NY Sigma
Variable N Mean StDev
SE Mean
NYM 120
1475919 123378 11263
Variable 95.0% CI
Z P
NYM
( 1453844, 1497993) 52.05 0.000
One Tailed Tests
One-Sample Z: New
York Profits
These two tests were performed to determine
if the New York profits were greater or less than the California profits.
Test of mu = 889739 vs mu > 889739
The assumed sigma = 123378 NY Sigma
Variable N Mean StDev
SE Mean
NYM 120
1475919 123378 11263
Variable
95.0% Lower Bound Z P
NYM 1457393
52.05 0.000
One-Sample Z: New
York Profits
Test of mu = 889739 vs mu < 889739
The assumed sigma = 123378 NY Sigma
Variable N Mean StDev
SE Mean
NYM 120
1475919 123378 11263
Variable
95.0% Upper Bound Z P
NYM 1494444
52.05 1.000
The
results of this test display that the New York profits were higher than the
California profits.
Summary of the Test of the Means
The mean price of east coast diesel is less
than west coast diesel.
The trucker weekly salaries were equal.
Mean
salary of New York process workers was less than the process workers in
California.
New
York profits were higher than the California profits.
Simple Linear Regression Analysis
Regression Analysis: CA
Profit versus West Coast Diesel Price
The regression equation is
CAM = 919267 - 22468 WC GAS
Predictor Coef SE Coef T P
Constant 919267 60861 15.10 0.000
WC GAS -22468 45954 -0.49 0.626
S = 82374 R-Sq = 0.2% R-Sq(adj) = 0.0%
Analysis of Variance
Source DF SS
MS F P
Regression 1
1621960521 1621960521 0.24
0.626
Residual Error 118 8.00679E+11 6785419288
Total 119 8.02301E+11
Unusual Observations
Obs WC GAS CAM Fit SE Fit Residual St Resid
42 1.34 1090325 889104 7631 201221 2.45R
48 1.39 1085479 887969 8345 197510 2.41R
68 1.12 1133048 894081
11636 238967 2.93R
69 1.16 1071235 893272 10429 177963 2.18R
70 1.16 1119303 893148 10255 226155 2.77R
100 1.71 935687 880825 19722
54862 0.69 X
101 1.71 903329 880943 19500 22386 0.28 X
118 1.19 724052 892570 9490 -168518 -2.06R
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the R-Squared value
and such a large p-value, diesel prices are not a good predictor of California
profits. We can not reject the null
hypothesis.
Regression Analysis: CA
Profit versus Process Workers CA
The regression equation is
CAM = 995012 - 150 PCA
Predictor Coef SE Coef T P
Constant 995012 87310 11.40 0.000
PCA -150.0
123.9 -1.21 0.229
S = 81950 R-Sq = 1.2% R-Sq(adj) = 0.4%
Analysis of Variance
Source DF SS
MS F P
Regression 1
9835731715 9835731715 1.46
0.229
Residual Error 118 7.92466E+11 6715811057
Total 119 8.02301E+11
Unusual Observations
Obs PCA CAM Fit SE Fit Residual St Resid
1 537 825999 914479 21769 -88480 -1.12 X
2 564 837479 910435 18666 -72956 -0.91 X
25 559 801538 911143
19204 -109605 -1.38 X
42 683 1090325 892519 7826 197806 2.42R
48 635 1085479 899848 11214 185631 2.29R
68 728 1133048 885897 8127
247151 3.03R
69 696 1071235 890616 7516 180619 2.21R
70 744 1119303 883420 9123 235883 2.90R
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the R-Squared value
and large p-value, process worker salaries are not a good predictor of
California profits. We can not reject
the null hypothesis.
Regression Analysis: CA
Profit versus Truckers CA
The regression equation is
CAM = 1028215 - 231 TCA
Predictor Coef SE Coef T P
Constant 1028215 124040 8.29 0.000
TCA -231.4
206.9 -1.12 0.266
S = 82023 R-Sq = 1.0% R-Sq(adj) = 0.2%
Analysis of Variance
Source DF SS
MS F P
Regression 1
8415627595 8415627595 1.25
0.266
Residual Error 118 7.93886E+11 6727845838
Total 119 8.02301E+11
Unusual Observations
Obs TCA CAM Fit SE Fit Residual St Resid
42 576 1090325 894946 8817 195379 2.40R
48 599 1085479 889560 7489 195919 2.40R
68 610
1133048 887124 7844 245924 3.01R
69 604 1071235 888468 7573 182767 2.24R
70 616 1119303 885724 8304 233579 2.86R
R denotes an observation with
a large standardized residual

Based on the R-Squared value
and such a large p-value, Truckers salaries are not a good predictor of
California profits. We can not reject
the null hypothesis.
Regression Analysis: CA
Profit versus Poultry Price
The regression equation is
CAM = - 131895 + 791402 PP
Predictor Coef SE Coef T P
Constant -131895 14405 -9.16 0.000
PP 791402
11124 71.14 0.000
S = 12446 R-Sq = 97.7% R-Sq(adj) = 97.7%
Analysis of Variance
Source DF SS
MS F P
Regression 1 7.84023E+11 7.84023E+11 5061.55
0.000
Residual Error 118 18277960962 154897974
Total 119 8.02301E+11
Unusual Observations
Obs PP CAM Fit SE Fit Residual St Resid
1 1.17 825999 794045 1761 31954 2.59R
2 1.19 837479 809873 1597 27606 2.24R
25 1.14 801538 770303 2027 31235 2.54R
42 1.54 1090325 1086864 2995 3461 0.29 X
48 1.52 1085479 1071036 2790 14443 1.19 X
68 1.60 1133048 1134348 3621 -1300 -0.11 X
69 1.52 1071235 1071036 2790 199 0.02 X
70 1.59 1119303 1126434 3516 -7131 -0.60 X
R denotes an observation with
a large standardized residual
X denotes an observation whose
X value gives it large influence.

Based on the high R-Squared
value and such a small p-value, poultry prices could be considered good
predictor of California profits. We can
reject the null hypothesis.
Regression Analysis: NY
Profits versus Poultry Price
The regression equation is
NYM = - 74829 + 1201276 PP
Predictor Coef SE Coef T P
Constant -74829 7536 -9.93 0.000
PP 1201276
5820 206.41 0.000
S = 6511 R-Sq = 99.7% R-Sq(adj) = 99.7%
Analysis of Variance
Source DF SS
MS F P
Regression 1 1.80643E+12 1.80643E+12 42606.45
0.000
Residual Error 118
5002959891 42397965
Total 119 1.81143E+12
Unusual Observations
Obs PP NYM Fit SE Fit Residual St Resid
13 1.16 1336224 1318652 966 17572 2.73R
14 1.29 1490566 1474817 594 15749 2.43R
15 1.34 1548627 1534881
659 13746 2.12R
42 1.54 1773017 1775136 1567 -2119 -0.34 X
48 1.52 1739709 1751111 1460 -11402 -1.80 X
68 1.60 1852431 1847213 1894 5218 0.84 X
69 1.52 1750430 1751111 1460 -681 -0.11 X
70 1.59 1837179 1835200 1839 1979 0.32 X
107 1.30 1471152 1486830 597 -15678 -2.42R
108 1.22 1368258 1390728 724 -22470 -3.47R
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the large R-Squared
value and such a small p-value, poultry prices are a good predictor of New York
profits. We can reject the null
hypothesis.
Regression Analysis: NY
Profits versus East Coast Diesel Price
The regression equation is
NYM = 1506806 - 26778 EC GAS
Predictor Coef SE Coef T P
Constant 1506806 85140 17.70 0.000
EC GAS -26778 73160 -0.37 0.715
S = 123829 R-Sq = 0.1% R-Sq(adj) = 0.0%
Analysis of Variance
Source DF SS MS
F P
Regression 1
2054267811 2054267811 0.13
0.715
Residual Error 118 1.80938E+12 15333688724
Total 119 1.81143E+12
Unusual Observations
Obs EC GAS NYM Fit SE Fit Residual St Resid
42 1.08 1773017 1477905 12540 295112 2.40R
48 1.16 1739709 1475643 11329 264066 2.14R
68 1.00 1852431 1479987 15854 372444 3.03R
69 0.99 1750430 1480188
16243 270242 2.20R
70 1.01 1837179 1479853 15600 357326 2.91R
98 1.54 1518981 1465520 30575 53461 0.45 X
99 1.51 1554798 1466357 28463 88441 0.73 X
109 1.55 1464805 1465393 30898 -588 -0.00 X
110 1.56 1456754 1464958 32008 -8204 -0.07 X
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the R-Squared value
and such a large p-value, diesel prices are not a good predictor of New York
profits. We can not reject the null
hypothesis.
Regression Analysis: NY
Profits versus Process Workers Weekly Salary NY
The regression equation is
NYM = 1775009 - 521 PNY
Predictor Coef SE Coef T P
Constant 1775009 144101 12.32 0.000
PNY -521.2
250.4 -2.08 0.040
S = 121685 R-Sq = 3.5% R-Sq(adj) = 2.7%
Analysis of Variance
Source DF SS
MS F P
Regression 1 64170222237 64170222237 4.33
0.040
Residual Error 118 1.74726E+12 14807282331
Total 119 1.81143E+12
Unusual Observations
Obs PNY NYM Fit SE Fit Residual St Resid
13 471 1336224 1529719 28130 -193495 -1.63 X
42 562 1773017 1482287 11522 290730 2.40R
48 660 1739709 1430851
24332 308858 2.59R
60 697 1317869 1411565 32848 -93696 -0.80 X
68 541 1852431 1492962 13799 359469 2.97R
69 541 1750430 1492915
13786 257515 2.13R
70 538 1837179 1494791 14338 342388 2.83R
84 673 1504509 1424184 27221 80325 0.68 X
108 741 1368258 1388641 43372 -20383 -0.18 X
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the low R-Squared
value and low p-value, process workers weekly salaries are not a good predictor
of New York profits. We can not reject
the null hypothesis, though we have to keep in mind that the low P-value
reduces the probability of this being the correct decision.
Regression Analysis: NY Profits versus Truckers Weekly Salary NY
The regression equation is
NYM = 1683352 - 351 TNY
Predictor Coef SE Coef T P
Constant 1683352 164223 10.25 0.000
TNY -351.3
277.5 -1.27 0.208
S = 123066 R-Sq = 1.3% R-Sq(adj) = 0.5%
Analysis of Variance
Source DF SS
MS F P
Regression 1 24277605903 24277605903 1.60
0.208
Residual Error 118 1.78715E+12 15145355351
Total 119 1.81143E+12
Unusual Observations
Obs TNY NYM Fit SE Fit
Residual St Resid
29 558 1241833 1487214 14346 -245381 -2.01R
42 572 1773017 1482541 12392 290476 2.37R
48 590 1739709 1475954 11234 263755 2.15R
68 579 1852431 1480005 11689 372426 3.04R
69 584 1750430 1478027 11357 272403 2.22R
70 591 1837179 1475581 11238 361598 2.95R
120 684 1318840 1442987 28333 -124147 -1.04 X
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the R-Squared value
and a large p-value, Truckers weekly salaries are not a good predictor of New
York profits. We can not reject the
null hypothesis.
Regression Analysis: NY
Profits versus CA Profits
The regression equation is
NYM = 150048 + 1.49 CAM
Predictor Coef SE Coef T P
Constant 150048 15855 9.46 0.000
CAM 1.49018
0.01774 83.98 0.000
S = 15894 R-Sq = 98.4% R-Sq(adj) = 98.3%
Analysis of Variance
Source DF SS
MS F P
Regression 1 1.78162E+12 1.78162E+12 7052.42
0.000
Residual Error 118 29809789938 252625338
Total 119 1.81143E+12
Unusual Observations
Obs CAM NYM Fit SE Fit Residual St Resid
1 825999 1332549 1380935
1840 -48386 -3.06R
2 837479 1356116 1398042 1722 -41926 -2.65R
23 776172 1270369 1306684 2483 -36315 -2.31R
25 801538 1304446 1344483
2134 -40037 -2.54R
42 1090325 1773017 1774828 3844 -1811 -0.12 X
48 1085479 1739709 1767607 3764 -27898 -1.81 X
68 1133048 1852431 1838493 4555 13938
0.92 X
70 1119303 1837179 1818010 4324 19169 1.25 X
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.

Based on the large R-Squared
value and such a small p-value, NY profits are a good predictor of California
profits. We can reject the null
hypothesis.
Regression Summary
NY profits are a good predictor of California
profits due to the large R-Squared value and such a small p-value.
California
Diesel prices are not a good predictor of
California profits due to the R-Squared value and such a large p-value.
Process worker salaries are not a good
predictor of California profits based on the R-Squared value and large p-value
Truckers salaries are not a good predictor of
California profits due to the R-Squared value and such a large p-value.
Poultry prices could be considered good predictor
of California profit due to the high R-Squared value and such a small p-value.
New
York
Diesel prices are not a good predictor of New
York profits due to the R-Squared value and such a large p-value.
Based on the low R-Squared value and low
p-value, process workers weekly salaries are not a good predictor of New York
profits. We can not reject the null
hypothesis, though we have to keep in mind that the low P-value reduces the
probability of this being the correct decision.
Truckers weekly salaries are not a good
predictor of New York profits due to the R-Squared value and a large p-value.
Poultry prices are a good predictor of New
York profits due to the large R-Squared value and such a small p-value.
Quadratic and Cubic Regressions
Previously,
linear regressions were used for all of the data sets versus the New York
Profits. The following section uses
Quadratic and Cubic regressions on the datasets which had an unfavorable
P-value. This occurred because the data
did not have a linear behavior.
California
Profits vs. West Coast Diesel Prices

Polynomial Regression
Analysis: CAM versus WC GAS
The regression equation
is
CAM = 1251908 - 516464 WC
GAS
+ 180495 WC GAS**2
S = 82565.8 R-Sq = 0.6 % R-Sq(adj) = 0.0 %
Analysis of Variance
Source DF SS MS F P
Regression 2
4.699E+09 2.349E+09 0.344622
0.709
Error 117 7.976E+11 6.817E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
1.622E+09 0.239036 0.626
Quadratic 1
3.077E+09 0.451320 0.503

Polynomial Regression Analysis:
CAM versus WC GAS
The regression equation
is
CAM = 5349413 - 9677988 WC
GAS
+ 6938727 WC GAS**2 - 1644348 WC GAS**3
S = 82551.4 R-Sq = 1.5 % R-Sq(adj)
= 0.0 %
Analysis of Variance
Source DF SS MS F P
Regression 3
1.179E+10 3.931E+09 0.576789
0.631
Error 116 7.905E+11 6.815E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
1.622E+09 0.23904 0.626
Quadratic 1
3.077E+09 0.45132 0.503
Cubic 1
7.093E+09 1.04088 0.310
The above regressions show that by using a
cubic regression a better fit is achieved for the regression of West Coast
Diesel Prices vs. California profits.
California
Profits vs. Process Workers Weekly Salary

Polynomial Regression Analysis:
CAM versus PCA
The regression equation
is
CAM = -3221303 + 12054.8
PCA
- 8.76512 PCA**2
S = 72268.9 R-Sq = 23.8 %
R-Sq(adj) = 22.5 %
Analysis of Variance
Source DF SS MS F P
Regression 2
1.912E+11 9.562E+10 18.3076
0.000
Error 117 6.111E+11 5.223E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
9.836E+09 1.4646 0.229
Quadratic 1
1.814E+11 34.7321 0.000

Polynomial Regression
Analysis: CAM versus PCA
The regression equation
is
CAM = 7368846 - 34812.4
PCA
+ 59.9047 PCA**2 - 0.0333174 PCA**3
S = 71518.4 R-Sq = 26.0 % R-Sq(adj) = 24.1 %
Analysis of Variance
Source DF SS MS F P
Regression 3
2.090E+11 6.966E+10 13.6187
0.000
Error 116 5.933E+11 5.115E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
9.836E+09 1.4646 0.229
Quadratic 1
1.814E+11 34.7321 0.000
Cubic 1
1.774E+10 3.4684 0.065
The conclusion of this series of regressions
is that the quadratic regression represents the behavior of the Process Workers
weekly salary vs. California Profits.
This is shown by the P-value of zero.
California
Profits vs. Truckers Weekly Salary

Polynomial Regression
Analysis: CAM versus TCA
The regression equation
is
CAM = -14149060 + 50852.8
TCA
- 42.8262 TCA**2
S = 69126.0 R-Sq = 30.3 % R-Sq(adj) = 29.1 %
Analysis of Variance
Source DF SS MS F P
Regression 2
2.432E+11 1.216E+11 25.4507
0.000
Error 117 5.591E+11 4.778E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
8.416E+09 1.2509 0.266
Quadratic 1
2.348E+11 49.1403 0.000

Polynomial Regression
Analysis: CAM versus TCA
The regression equation
is
CAM = -46612100 + 214266
TCA
- 316.469 TCA**2 + 0.152438 TCA**3
S = 69211.5 R-Sq = 30.7 % R-Sq(adj) = 28.9 %
Analysis of Variance
Source DF SS MS F P
Regression 3
2.466E+11 8.221E+10 17.1623
0.000
Error 116 5.557E+11 4.790E+09
Total 119 8.023E+11
Source DF
Seq SS F P
Linear 1
8.416E+09 1.2509 0.266
Quadratic 1
2.348E+11 49.1403 0.000
Cubic 1
3.406E+09 0.7111 0.401
The conclusion of this series of regressions
is that the best description of the behavior of the Truckers Weekly salary vs.
California Profits is as a quadratic.
Regression of New York Profits vs. East Coast
Diesel Prices

Polynomial Regression
Analysis: NYM versus EC GAS
The regression equation
is
NYM = 2127301 - 1059063 EC
GAS
+ 421017 EC GAS**2
S = 123847 R-Sq = 0.9 % R-Sq(adj) = 0.0 %
Analysis of Variance
Source DF SS MS F P
Regression 2
1.688E+10 8.438E+09 0.550117
0.578
Error 117 1.795E+12 1.534E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
2.054E+09 0.133971 0.715
Quadratic 1
1.482E+10 0.966301 0.328

Polynomial Regression
Analysis: NYM versus EC GAS
The regression equation
is
NYM = 3989944 - 5763650 EC
GAS
+ 4333049 EC GAS**2 - 1070097 EC GAS**3
S = 124277 R-Sq = 1.1 % R-Sq(adj) = 0.0 %
Analysis of Variance
Source DF SS MS F P
Regression 3
1.983E+10 6.609E+09 0.427916
0.733
Error 116 1.792E+12 1.544E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
2.054E+09 0.133971 0.715
Quadratic 1
1.482E+10 0.966301 0.328
Cubic 1
2.952E+09 0.191123 0.663
The conclusion of this series of regressions
is that the best description of the behavior of the East Coast Diesel Prices
vs. New York Profits is as a quadratic.
Regression of New York Profits vs. Process
Worker Weekly Salary

Polynomial Regression
Analysis: NYM versus PNY
The regression equation
is
NYM = 859054 + 2624.91
PNY
- 2.68499 PNY**2
S = 121878 R-Sq = 4.1 % R-Sq(adj) = 2.4 %
Analysis of Variance
Source DF SS MS F P
Regression 2
7.348E+10 3.674E+10 2.47350
0.089
Error 117 1.738E+12 1.485E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
6.417E+10 4.33369 0.040
Quadratic 1
9.314E+09 0.62701 0.430

Polynomial Regression
Analysis: NYM versus PNY
The regression equation
is
NYM = -9654218 + 56071.6
PNY
- 92.5947 PNY**2 + 0.0500370 PNY**3
S = 121632 R-Sq = 5.3 % R-Sq(adj)
= 2.8 %
Analysis of Variance
Source DF SS MS F P
Regression 3
9.527E+10 3.176E+10 2.14661
0.098
Error 116 1.716E+12 1.479E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
6.417E+10 4.33369 0.040
Quadratic 1
9.314E+09 0.62701 0.430
Cubic 1
2.179E+10 1.47282 0.227
The conclusion of this series of regressions
is that the best description of the behavior of the Process Workers Weekly
Salary vs. New York Profits is as a quadratic.
Regression of New York Profits vs. Truckers
Weekly Salary

Polynomial Regression
Analysis: NYM versus TNY
The regression equation
is
NYM = -10013629 + 39291.2
TNY
- 33.4312 TNY**2
S = 106805 R-Sq = 26.3 % R-Sq(adj) = 25.1 %
Analysis of Variance
Source DF SS MS F P
Regression 2
4.768E+11 2.384E+11 20.8974
0.000
Error 117 1.335E+12 1.141E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
2.428E+10 1.6030 0.208
Quadratic 1
4.525E+11 39.6667 0.000

Polynomial Regression
Analysis: NYM versus TNY
The regression equation
is
NYM = -41244665 + 197822
TNY
- 300.724 TNY**2 + 0.149698 TNY**3
S = 106480 R-Sq = 27.4 % R-Sq(adj) = 25.5 %
Analysis of Variance
Source DF SS MS F P
Regression 3
4.962E+11 1.654E+11 14.5886
0.000
Error 116 1.315E+12 1.134E+10
Total 119 1.811E+12
Source DF
Seq SS F P
Linear 1
2.428E+10 1.6030 0.208
Quadratic 1
4.525E+11 39.6667 0.000
Cubic 1
1.945E+10 1.7153 0.193
The conclusion of this series of regressions
is that the best description of the behavior of the Truckers Weekly Salary vs.
New York Profits is as a quadratic.
Summary of Cubic and
Quadratic Regression Analysis
A better fit is
achieved for the regression of West Coast Diesel Prices vs. California profits
when a cubic regression was used.
A quadratic
regression represents the behavior of the Process Workers weekly salary vs.
California Profits.
The best
description of the behavior of the Truckers Weekly salary vs. California
Profits is as a quadratic.
The best
description of the behavior of the East Coast Diesel Prices vs. New York
Profits is as a quadratic.
The best
description of the behavior of the Process Workers Weekly Salary vs. New York
Profits is as a quadratic.
The best
description of the behavior of the Truckers Weekly Salary vs. New York Profits
is as a quadratic.
Multiple
Regression
Regression Analysis: CAM
versus PP, WC GAS, Process workers CA, TCA
The regression equation is
CAM = 3567 + 795954 PP - 2749
WC GAS - 199 PCA + 2.9 TCA
Predictor Coef SE Coef T P
Constant 3567 4785 0.75 0.458
PP 795954
2119 375.55 0.000
WC GAS -2749 1599 -1.72 0.088
PCA -198.702
8.403 -23.65 0.000
TCA 2.92
14.65 0.20 0.842
S = 2369 R-Sq = 99.9% R-Sq(adj) = 99.9%
Analysis of Variance
Source DF SS
MS F
P
Regression 4 8.01656E+11 2.00414E+11 35705.94
0.000
Residual Error 115
645483854 5612903
Total 119 8.02301E+11
Source DF
Seq SS
PP 1 7.84023E+11
WC GAS 1
4913782411
PCA 1 12718471709
TCA 1 222988
The multiple regression equation reaffirms
that Poultry Price is the most predictable factor for profits. We see that the P-value is very significant
for this variable. The WC GAS and the
Process Workers are the next predictors of profit. Finally the Truckers salary
shows no evidence it adds to the predictability of profits with such a high p-
value.
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Regression Analysis: NYM
versus PP, EC GAS, PNY, TNY
The regression equation is
NYM = 5455 + 1194226 PP -
6731 EC GAS - 111 PNY + 0.7 TNY
Predictor Coef SE Coef T P
Constant 5455 6876 0.79 0.429
PP 1194226
3206 372.45 0.000
EC GAS -6731 2499 -2.69 0.008
PNY -111.251 9.886 -11.25 0.000
TNY 0.71
10.85 0.07 0.948
S = 3539 R-Sq = 99.9% R-Sq(adj) = 99.9%
Analysis of Variance
Source DF SS
MS F P
Regression 4 1.80999E+12 4.52497E+11
36121.31 0.000
Residual Error 115
1440622644 12527153
Total 119 1.81143E+12
Source DF
Seq SS
PP 1 1.80643E+12
EC GAS 1
1397294839
PNY 1 2164989141
TNY 1 53267
Unusual Observations
Obs PP NYM Fit SE Fit Residual St Resid
101 1.32 1512449 1505428 760 7021 2.03R
108 1.22 1368258 1371169 1318 -2911 -0.89 X
R denotes an observation with
a large standardized residual
X denotes an observation
whose X value gives it large influence.
The multiple regression equation reaffirms
that Poultry Price is the most predictable factor for profits. We see that the P-value is very significant
for this variable. The EC GAS and the
Process Workers are the next predictors of profit. Finally the Truckers salary shows no evidence it adds to
the predictability of profits with such a high p- value.
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Summary of
Multiple Regression Analysis
The multiple regression equation reaffirms
that Poultry Price is the most predictable factor for profits. The P-value is very significant for this
variable. The WC GAS and the Process
Workers are the next predictors of profit. Finally the Truckers salary shows no
evidence it adds to the predictability of profits with such a high p- value.
The multiple regression equation reaffirms
that Poultry Price is the most predictable factor for profits. The P-value is very significant for this
variable. The EC GAS and the Process
Workers are the next predictors of
profit. Finally the Truckers salary shows no evidence it adds to the
predictability of profits with such a high p- value.
ANOVA
California ANOVAs
One-way ANOVA: CAM versus PP
Ho: The variances of the Poultry prices are
equal
H1: The variances are not equal
Analysis of Variance for CAM
Source
DF SS MS F P
PP
37 7.910E+11 2.138E+10
155.64 0.000
Error
82 1.126E+10 137364841
Total
119 8.023E+11
The
variances are not equal.
One-way ANOVA: CAM versus PCA
Ho: The variances of the Process workers
salaries are equal
H1: The variances are not equal
Analysis of Variance for CAM
Source
DF SS MS F P
PCA
113 7.798E+11 6.901E+09
1.84 0.225
Error
6 2.246E+10 3.743E+09
Total
119 8.023E+11
The
variances are equal.
One-way ANOVA: CAM versus WC GAS
Ho: The variances of the WC Gas prices are
equal
H1: The variances are not equal
Analysis of Variance for CAM
Source
DF SS MS F P
WC GAS
118 7.974E+11 6.757E+09
1.37 0.606
Error
1 4.949E+09 4.949E+09
Total
119 8.023E+11
Analysis of Variance for
CAM
Source DF
SS MS F P
WC GAS 118 7.974E+11 6.757E+09 1.37
0.606
Error 1 4.949E+09 4.949E+09
Total 119 8.023E+11
The
variances are equal.
Below
is the printout of the ANOVA between the California Profits and West Coast
Diesel Prices.
Individual 95% CI’s For Mean
Based on Pooled StDev (See Table Below)
|
Level
N Mean StDev
---+---------+---------+---------+--- 1.03675 1
884923 0 (--------------*--------------) 1.06725
1 920597 0 (--------------*--------------) 1.07950
1 824779 0 (--------------*--------------) 1.08775
1 952282 0 (--------------*--------------) 1.10625
1 944466 0 (--------------*--------------) 1.10950
1 911293 0 (--------------*--------------) 1.10975
1 863378 0 (--------------*--------------) 1.11100
1 944624 0
(--------------*--------------) 1.11850
1 944733 0 (--------------*--------------) 1.12000
1 917475 0 (--------------*--------------) 1.12100
1 1133048 0 (--------------*--------------) 1.12625
1 1019580 0 (--------------*--------------) 1.12775
1 959569 0 (--------------*--------------) 1.13075
1 803858 0
(--------------*--------------) 1.13700
1 944570 0 (--------------*--------------) 1.14025
1 946585 0 (--------------*--------------) 1.14550
1 958574 0 (--------------*--------------) 1.15325
1 856571 0 (--------------*--------------) 1.15450
1 875455 0 (--------------*-------------) 1.15625
1 1014554 0 (--------------*--------------) 1.15700
1 1071235 0 (--------------*--------------) 1.15775
1 862812 0 (--------------*--------------) 1.16250
1 1119303 0 (--------------*--------------) 1.16425
1 826425 0 (--------------*--------------) 1.16550
1 829097 0 (--------------*--------------) 1.16650 1 890019 0
(--------------*--------------) 1.17200
1 866804 0 (-------------*--------------) 1.17775
1 865813 0 (-------------*--------------) 1.18150
1 814100 0 (--------------*-------------) 1.18200
1 766514 0
(--------------*--------------) 1.18500
1 822676 0 (--------------*--------------) 1.18825
1 724052 0
(--------------*--------------) 1.19025
1 763086 0
(--------------*--------------) 1.19475
1 837479 0 (--------------*--------------) 1.20175
1 965858 0 (--------------*--------------) 1.20525
1 807753 0 (-------------*--------------) 1.20600
1 884349 0 (--------------*--------------) 1.20975
1 825999 0 (--------------*--------------) 1.21050
1 816757 0 (--------------*--------------) 1.21150
1 826824 0 (--------------*--------------) 1.22125
1 741004 0
(--------------*--------------) 1.22450
1 729828 0
(--------------*--------------) 1.22575
1 893279 0 (--------------*--------------) 1.22600
1 776172 0
(--------------*--------------) 1.22650
1 848657 0 (--------------*--------------) 1.22775
1 820962 0 (--------------*--------------) 1.22875
1 821720 0 (--------------*--------------) 1.22925
1 786182 0 (--------------*--------------) 1.23100
1 801538 0
(--------------*--------------) 1.23700
1 880611 0 (--------------*--------------) 1.24500
1 946625 0 (--------------*--------------) 1.25300
1 1005833 0 (--------------*--------------) 1.25325
1 993720 0 (--------------*-------------) 1.26075
1 831341 0 (--------------*--------------) 1.26100
1 967362 0 (--------------*--------------) 1.26825
1 918509 0 (--------------*--------------) 1.26900
1 1025322 0 (--------------*--------------) 1.27475
1 928116 0 (-------------*--------------) 1.27700
1 947466 0 (--------------*--------------) 1.27775
1 844446 0 (--------------*--------------) |
1.28025
1 903828 0 (--------------*--------------) 1.28125
1 856788 0 (--------------*--------------) 1.28425
1 792120 0
(--------------*--------------) 1.29100
1 800508 0
(--------------*--------------) 1.29625
1 951052 0 (--------------*--------------) 1.30650
1 908793 0 (--------------*--------------) 1.30725
1 959355 0 (--------------*--------------) 1.31850
1 880936 0 (--------------*--------------) 1.32200
1 1001176 0 (--------------*--------------) 1.32600
1 917105 0 (--------------*--------------) 1.33225
1 904465 0 (--------------*--------------) 1.33350
1 912564 0 (--------------*--------------) 1.34250
2 1040580 70350 (---------*----------) 1.34625
1 834574 0 (--------------*--------------) 1.34800
1 961802 0 (--------------*--------------) 1.35025
1 930313 0 (--------------*-------------) 1.35250
1 802940 0
(--------------*--------------) 1.35450
1 840965 0 (--------------*--------------) 1.35500
1 792711 0
(--------------*--------------) 1.35675
1 817369 0 (--------------*--------------) 1.36100
1 870275 0 (--------------*-------------) 1.36775
1 806333 0 (-------------*--------------) 1.37175
1 1025152 0 (--------------*--------------) 1.37925
1 873550 0
(--------------*-------------) 1.38525
1 844337 0 (--------------*--------------) 1.38875
1 777387 0
(--------------*--------------) 1.38925
1 844731 0 (--------------*--------------) 1.39175
1 773789 0
(--------------*--------------) 1.39300
1 1085479 0 (--------------*--------------) 1.39475
1 801560 0
(--------------*--------------) 1.39725
1 871834 0 (--------------*-------------) 1.41075
1 1022339 0 (--------------*--------------) 1.41750
1 833385 0 (--------------*--------------) 1.43300
1 989538 0 (-------------*--------------) 1.44725
1 944021 0 (--------------*--------------) 1.46650
1 999264 0 (--------------*--------------) 1.47300
1 991471 0 (--------------*-------------) 1.50175
1 843922 0 (--------------*--------------) 1.50975
1 800790 0
(--------------*--------------) 1.51775
1 894032 0 (--------------*--------------) 1.53000
1 837929 0 (--------------*--------------) 1.53750
1 887699 0 (--------------*--------------) 1.54650
1 888880 0 (--------------*--------------) 1.54950
1 922948 0 (--------------*--------------) 1.56125
1 885759 0 (--------------*--------------) 1.56250
1 839317 0 (--------------*--------------) 1.57400
1 819198 0 (--------------*--------------) 1.59300
1 870309 0 (--------------*-------------) 1.59425
1 897253 0 (--------------*--------------) 1.59775
1 875113 0 (--------------*-------------) 1.61625
1 869396 0 (-------------*--------------) 1.61775
1 874251 0 (--------------*-------------) 1.62675
1 921422 0
(--------------*--------------) 1.63650
1 808090 0 (-------------*--------------) 1.64625
1 930315 0 (--------------*-------------) 1.65825
1 869783 0 (-------------*--------------) 1.67425
1 871713 0 (--------------*-------------) 1.70575
1 903329 0 (--------------*--------------) 1.71100
1 935687 0 (--------------*-------------) ---+---------+---------+---------+--- Pooled StDev =
70350 0 600000
1200000 1800000 |
One-way ANOVA: CAM versus TCA
Ho: The variances of the Truckers Wages are
equal
H1: The variances are not equal
Analysis of Variance for CAM
Source
DF SS MS F P
TCA
116 7.716E+11 6.652E+09
0.65 0.792
Error
3 3.073E+10 1.024E+10
Total
119 8.023E+11
The
Variances are equal
New York ANOVAs
One-way ANOVA: NYM versus PP
Ho: The variances of the Poultry prices are
equal
H1: The variances are not equal
Analysis of Variance for NYM
Source
DF SS MS F P
PP
37 1.808E+12 4.886E+10
1113.99 0.000
Error
82 3.597E+09 43860497
Total
119 1.811E+12
The
variances are not equal
Below is the printout of the ANOVA between New York Profits and
Poultry Prices.
Individual 95% CIs For Mean Based
on Pooled StDev
Level N
Mean StDev ---------+---------+---------+-------
1.09 1
1241833 0 (*)
1.11 2
1254631 2064 (*
1.12 1
1270369 0 (*
1.13 1
1283305 0 *)
1.14 1
1304446 0 *)
1.16 3
1322036 12630 *
1.17 5
1327393 9575 *)
1.18 2
1343455 8784 *)
1.19 7
1355575 4134 *
1.20 6
1365406 4989 *)
1.21 2
1376892 6568 (*
1.22 3 1382181 13137 *
1.23 6
1404137 3059 *
1.24 4
1418956 6543 *
1.25 6
1427164 6129 *)
1.26 3
1445106 1245 *)
1.27 2
1452971 5145 (*
1.28 4
1460118 6920 *
1.29 9
1473707 8711 (*
1.30 3
1482511 10493 *)
1.31 2
1489536 2951 *)
1.32 4
1509259 3664 *)
1.33 5
1521710 3657 *
1.34 3
1539267 8826 *
1.35 5
1549734 4494 *)
1.36 5
1559067 6481 *
1.37 3
1572564 7686 (*
1.38 4
1583473 2925 *)
1.39 1
1596430 0 (*
1.41 2
1625594 3405 *)
1.42 3
1632712 5929 (*
1.43 2
1646320 6397 *)
1.45 3
1665205 2997 *)
1.46 2
1674091 1205 (*
1.52 2
1745070 7581 *)
1.54 1
1773017 0 (*
1.59 1
1837179 0 (*)
1.60 1
1852431 0 (*
---------+---------+---------+-------
Pooled StDev = 6623 1400000
1600000 1800000
One-way ANOVA: NYM versus TNY
Ho: The variances of the Truckers Wages are
equal
H1: The variances are not equal
Analysis of Variance for NYM
Source
DF SS MS F P
TNY
116 1.804E+12 1.555E+10
6.16 0.078
Error
3 7.573E+09 2.524E+09
Total
119 1.811E+12
The variances are equal.
One-way ANOVA: NYM versus EC GAS
Ho: The variances of the EC Gas Prices are equal
H1: The variances are not equal
Analysis of Variance for NYM
Source
DF SS MS F P
EC GAS
114 1.728E+12 1.516E+10
0.91 0.636
Error
5 8.345E+10 1.669E+10
Total
119 1.811E+12
The
variances are equal
Summary of ANOVA Analysis
California
The variance of the California profits was
not equal to the variance of the poultry prices. However, the variance of the
California profits was equal to the variance of the Process Workers, Gas
Prices, and Truckers.
New
York
The variance of the New York profits was
not equal to the variance of the poultry prices. However, the variance of the
New York profits were equal to the variance of the Process Workers, Gas Prices,
and Truckers.
Two Sample T-Test of the
Means (Small Sample)
The following T-tests were performed on a
small sample of the data. In this case
the sample chosen was the data from the year 1993 (12 data points). Comparisons of the variances were first
performed, followed by the T-test. The
results are shown below.
Test for Equal Variances,
Diesel Prices
Level1 WC GAS
Level2 EC GAS
ConfLvl 95.0000
Bonferroni confidence
intervals for standard deviations

Lower Sigma Upper N Factor Levels
1.36E-02 2.01E-02
3.71E-02 12 WC GAS
1.05E-02 1.56E-02
2.88E-02 12 EC GAS
F-Test (normal distribution)
Test Statistic: 1.659
P-Value : 0.414
Levene's Test (any continuous
distribution)
Test Statistic: 0.401
P-Value : 0.533
The
results of this test suggest that assumption of equal variances is correct with
a probability of .533.
Two-Sample T-Test and CI:
West Coast Diesel, East Coast Diesel
Two-sample T for WC GAS vs EC
GAS
N Mean StDev
SE Mean
WC GAS 12
1.1775 0.0201 0.0058
EC GAS 12
1.0533 0.0156 0.0045
Difference = mu WC GAS - mu
EC GAS
Estimate for difference: 0.12417
95% CI for difference:
(0.10897, 0.13937)
T-Test of difference = 0 (vs
not =): T-Value = 16.94
P-Value = 0.000 DF = 22
Both use Pooled StDev =
0.0180
The
conclusion is that the means are not equal, this is based on the P-value of 0.
Test for Equal Variances
Process Workers
Level1 PNY
Level2 PCA
ConfLvl 95.0000
Bonferroni confidence
intervals for standard deviations

Lower Sigma Upper
N Factor Levels
21.0906 31.1891 57.6533
12 PNY
22.1087 32.6947 60.4364
12 PCA
F-Test (normal distribution)
Test Statistic: 0.910
P-Value : 0.879
Levene's Test (any continuous
distribution)