Refer to Exercise 9. In a separate experiment, 18 cars were outfitted with tires with

Chapter 5, Problem 10

(choose chapter or problem)

Refer to Exercise 9. In a separate experiment, 18 cars  were outfitted with tires with tread type A, and another 18 were outfitted with tires with tread type B.  Each car was driven 1000 miles. The cars with tread type A averaged \(23.93 \mathrm{mpg}), with a standard deviation of

\(1.79 \mathrm{mpg}\). The cars with tread type B averaged \(22.19 \mathrm{mpg}\), with a standard deviation of \(1.95 \mathrm{mpg}).

Which method should be used to find a con- fidence interval for the difference between the  mean mileages of the two tread types: expression (5.24) (in this section) or expression (5.21)  (in Section 5.6)?  

Using the appropriate method, find a 99% confidence interval for the difference between the mean  mileages of the two tread types.

Is the confidence interval found in part (b) wider than the one found in Exercise 9? Why is this so?

Equation Transcription:

Text Transcription:

23.93 mpg

1.79 mpg

22.19 mpg

1.95 mpg