# STATISTICS 503-A trucking company is planning to buy a new

June 21, 2017
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June 21, 2017

STATISTICS 503-A trucking company is planning to buy a new
A trucking company is planning to buy a new fleet of trucks. They have narrowed the choice to five models, each of which has about the same purchase price. It is decided to conduct a study to determine if there are any differences in the mean (average) direct operating cost of the trucks. Five different drivers were used in the study. Each truck is driven 1,000 miles by each driver and the direct cost per mile recorded. The following results were obtained. Truc
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II III IV V Driver I A 31 41 32 28 37 B 31 40 31 29 38 C 37 46 38 35 45 D 33 41 43 40 41 E 30 39 40 44 40 #9
What would the appropriate type of analysis be for this data? Two-Factor ANOVA (with replication)
Randomized Block ANOVA
Two-sample t-tests on each pairwise comparison of “Truck” means
One-Factor ANOVA
#10
The reason for requiring each type of truck to be driven by each driver is of no consequence in the final analysis
is to control for differences among the 5 trucks
is to allow for measuring the “interaction” between the 5 trucks and the 5 drivers
is to control for differences among the 5 drivers
#11
To provide the data necessary for this type of analysis, ____________ control must be used when assigning the drivers to the trucks as compared to “completely” randomly assigning the drivers to the
trucks. More
Less #12
If each driver operated the same truck for their five trials, you would be able to separate the differences due to the 5 trucks and the 5 drivers
would have “confounded” the effects between the type of truck and the drivers, and you
would not be able to separate the differences due to the 5 trucks and the 5 drivers
would be able to test for differences due to the 5 different drivers
would be able to test for differences due to the 5 different trucks
#13
In this analysis, the “blocking” factor would be: The &quot;truck&quot; factor
There wouldn’t be a &quot;blocking&quot; factor
The &quot;driver&quot; factor
#14
The appropriate null hypothesis, , for the study would be: ? =? =? =? =?
I II III IV V At least one pair of the µ’s (for the trucks) is different
All the pairs of the µ’s (for the trucks) are different ? =? =? =? =?
A B C D E #15
How many different truck “pairwise” comparisons are there? 15
5
10
6
#16
Using a level of significance = 0.05, should any of the truck pairwise comparisons be considered significantly different? No Yes
#17
Should the mean direct cost per mile for Truck III be considered significantly different from Truck V? No
Yes
#18
Do any of the trucks appear to be the best? Yes – Truck III
Yes – Truck II
Yes – Truck IV
Yes – Truck I
No – no one truck appears to be the best