Refer to Exercise 75. Construct and interpret a 95% confidence interval for the true mean difference (Weight – Groove) in the estimates of tire wear using these two methods in the population of tires.

Exercise 75.

Researchers were interested in comparing two methods for estimating tire wear. The first method used the amount of weight lost by a tire. The second method used the amount of wear in the grooves of the tire. A random sample of 16 tires was obtained. Both methods were used to estimate the total distance traveled by each tire. The table provides the two estimates (in thousands of miles) for each tire.

Tire Weight Groove Diff. Tire Weight Groove Diff. 1 45.9 35.7 10.2 9 30.4 23.1 7.3 41.9 39.2 2.7 10 27.3 23.7 3.6 3 37.5 31.1 6.4 11 20.4 20.9 -0.5 4 33.4 28.1 5.3 12 24.5 16.1 8.4 31.0 24.0 7.0 13 20.9 19.9 1.0 6 30.5 28.7 1.8 14 18.9 15.2 3.7 7 30.9 25.9 5.0 15 13.7 11.5 2.2 8 31.9 23.3 8.6 16 11.4 11.2 0.2 2.