Question

The Stinker Station convenience store chain wants to know if there is a difference in miles per gallon a car would get using three different grades of gasoline: regular, mid-range and premium. Because of the differences in the performance of different automobiles, seven different automobiles were selected and treated as blocks. Therefore, each grade of gasoline was tested with each type of automobile. The results of the trials, in miles per gallon, are shown in the following table.   At the 0.01 significance level, is there a difference in the types of gasoline or the different automobiles? List all the steps of the hypothesis test and do the calculations. (You need to test both the types of gasoline and the different automobiles.)

Automobile	Regular	Mid-grade	Premium
1	21	23	26
2	23	22	25
3	24	25	27
4	24	24	26
5	26	26	30
6	26	24	27
7	28	27	32

Answer 1