7.41 Fuel efficiency comparison t test. Refer to Exercise 7.32. In addition to the computer calculating miles per gallon, the driver also recorded the miles per gallon by dividing the miles driven by the number of gallons at fill-up. The driver wants to determine if these calculations are different.

431

Fill-up 1 2 3 4 5 6 7 8 9 10
Computer 41.5 50.7 36.6 37.3 34.2 45.0 48.0 43.2 47.7 42.2
Driver 36.5 44.2 37.2 35.6 30.5 40.5 40.0 41.0 42.8 39.2
Fill-up 11 12 13 14 15 16 17 18 19 20
Computer 43.2 44.6 48.4 46.4 46.8 39.2 37.3 43.5 44.3 43.3
Driver 38.8 44.5 45.4 45.3 45.7 34.2 35.2 39.8 44.9 47.5

  1. (a) State the appropriate H0 and Ha.

  2. (b) Carry out the test using a significance level of 0.05. Give the P-value, and then interpret the result.