Question: Martin Motors has in stock three cars of the same make and model. The president would like to compare the gas consumption of the three cars (labeled car A, car B, and car C) using four different types of gasoline. For each trial, a gallon of gasoline was added to an empty tank, and the car was driven until it ran out of gas. The following table shows the number of miles driven in each trial.

Using the .05 level of significance:

a. Is there a difference among types of gasoline?

b. Is there a difference in the cars?

Distance (miles)

Types of Gasoline Car A Car B Car C

Regular 22.4 20.8 21.5

Super regular 17.0 19.4 20.7

Unleaded 19.2 20.2 21.2

Premium unleaded 20.3 18.6 20.4