A consumer testing agency is interested in determining whether there is a difference in the mileage for

Question:

A consumer testing agency is interested in determining whether there is a difference in the mileage for three brands of gasoline. To test this, four different vehicles are driven with each of these gasoline. Results are shown in Table 12.18.
Test whether there is a difference between the three gasoline medians at the 0.05 level.
Table 12.18 Mileage by Gasoline Type