650-Q1

Total taxi fares are determined by distance travelled as well as the amount of time taken for the trip. In preparing to apply for a rate increase, the general manager of a fleet of taxis wanted to know the distance customers travel by taxi on the average trip

She organized a survey wherein she asked taxi drivers to record the number of miles (to the nearest one-tenth) travelled by randomly selected customers.

A sample of 41 customers was produced. The sample results appear below.

1. Construct a 95% confidence interval around the sample mean.
2. Be sure to show whether you use the t- or z- value, and interpret the meaning confidence interval in a single sentence. Also, state why you used either the "t" or the "z".

8.2, 9.1, 11.2, 5.0, 6.4, 9.5, 10.1, 7.9, 8.3, 6.8, 6.9, 7.9, 1.1, 6.7, 11.4, 6.9,

6.5, 8.0, 1.5, 8.2, 7.6, 14.1, 7.0, 10.0, 7.1, 8.0, 8.1, 4.4, 5.9, 2.3, 13.3, 9.2,

2.8, 13.0, 8.3, 10.4, 9.0, 3.5, 9.8, 6.5, 7.7