A rental car company wants to investigate whether the type of car rented affects the length of the rental period. An experiment is run for one week at a particular location, and 10 rental contracts are selected at random for each car type.

The results are shown in the following table.

Type of Car Observations Subcompact 3 5 3 7 6 5 3 2 1 6 Compact 1 3 4 7 5 6 3 2 1 7 Midsize 4 1 3 5 7 1 2 4 2 7 Fullsize 3 5 7 5 10 3 4 7 2 7

(a) Is there evidence to support a claim that the type of car rented affects the length of the rental contract? Use

???? = 0.05. If so, which types of cars are responsible for the difference?

(b) Analyze the residuals from this experiment and comment on model adequacy.

(c) Notice that the response variable in this experiment is a count. Should this cause any potential concerns about the validity of the analysis of variance?