Homework Sourse1 A national car rental agency is interested in determining
1. A national car rental agency is interested in determining whether the mean days that customers rent cars is the same between three of its major cities. The following data reflect the number of days people rented a car for a sample of people in each of three cities. Given this information, the correct null and alternative hypotheses are:
H0: ?1 = ?2 = ?3
Ha: not all ? j are equal.
Boston Dallas Seattle
5 7 7
3 7 5
7 11 8
1 5 11
2 7
............. . 3
true
false
2. An advertising company is interested in determining if there is a difference in the mean sales that will be generated for a soft drink company based on which shelf the soft drinks are located. There are four possible shelf levels. The ad company wants to control for store size. The following data reflect the sales for one week at each combination of shelf level and store size.
Level 1 Level 2 Level 3 Level 4
Small Store 300 200 500 200
Medium Store 400 180 600 200
Large Store 600 300 900 400
Based on the experimental design, the calculated F-test statistic value for testing whether blocking on store size was effective is approximately 16.3.
true
false
3. A test is conducted to compare three different income tax software packages to determine whether there is any difference in the average time it takes to prepare income tax returns using the three different software packages. Ten different persons\' income tax returns are done by each of the three software packages and the time is recorded for each. The computer results are shown below.
SUMMARY
Count
Sum
Average
Variance
1
3
9
3
1
2
3
30
10
1
3
3
12
4
0
4
3
6.5
2.166667
0.583333
5
3
25
8.333333
2.333333
6
3
7
2.333333
1.083333
7
3
10
3.333333
0.333333
8
3
18
6
1
9
3
33.5
11.16667
0.583333
10
3
4.5
1.5
0.25
Software A
10
47.5
4.75
12.95833
Software B
10
47.5
4.75
10.79167
Software C
10
60.5
6.05
13.46944
ANOVA
Source of Variation
SS
df
MS
F
P-value
F crit
Rows
329.9083
9
36.65648
130.227
1.6E-14
2.456281
Columns
11.26667
2
5.633333
20.01316
2.66E-05
3.554557
Error
5.066667
18
0.281481
Total
346.2417
29
Based on these results and using a 0.05 level of significance which is correct regarding blocking?
Blocking was not effective because p-value = 1.6 is greater than 0.05.
Blocking was not effective because p-value = 2.66 is greater than 0.05.
Blocking was effective because p-value = 1.6E-14 is less than 0.05.
Blocking was effective because p-value = 2.66E - 5 is less than 0.05.
| SUMMARY | Count | Sum | Average | Variance |
| 1 | 3 | 9 | 3 | 1 |
| 2 | 3 | 30 | 10 | 1 |
| 3 | 3 | 12 | 4 | 0 |
| 4 | 3 | 6.5 | 2.166667 | 0.583333 |
| 5 | 3 | 25 | 8.333333 | 2.333333 |
| 6 | 3 | 7 | 2.333333 | 1.083333 |
| 7 | 3 | 10 | 3.333333 | 0.333333 |
| 8 | 3 | 18 | 6 | 1 |
| 9 | 3 | 33.5 | 11.16667 | 0.583333 |
| 10 | 3 | 4.5 | 1.5 | 0.25 |
| Software A | 10 | 47.5 | 4.75 | 12.95833 |
| Software B | 10 | 47.5 | 4.75 | 10.79167 |
| Software C | 10 | 60.5 | 6.05 | 13.46944 |
Solution
(1) true
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(2) true
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(3)Blocking was effective because p-value = 2.66E - 5 is less than 0.05.
| Mean | n | Std. Dev | |
| 433.333 | 3 | 152.753 | Level 1 |
| 226.667 | 3 | 64.291 | Level 2 |
| 666.667 | 3 | 208.167 | Level 3 |
| 266.667 | 3 | 115.470 | Level 4 |
| 300.000 | 4 | 141.421 | Small |
| 345.000 | 4 | 196.893 | Medium |
| 550.000 | 4 | 264.575 | Large |
| 398.333 | 12 | 219.165 | Total |
