Question

Suppose average pizza delivery times are normally distributed with an unknown population mean and a population standard deviation of six minutes. A random sample of 28 pizza delivery restaurants is taken and has a sample mean delivery time of 36 minutes. Find a 90% confidence interval estimate for the population mean delivery time.

Answer 1

90% confidence interval = (34.069,37.931)

Explanation:

90% 1.645

Xbar / Point Est. 36

µ 0

σ 6

n 28

Confidence Interval

(34.069,37.931)