The waiting time to place an order in a fast-food restaurant is normally distributed with a population standard deviation of 1.2 minutes. The sample mean is 5.1 minutes from a sample of 25 orders. What is the 95% confidence interval estimate of the population mean waiting time to place an order? [Hints: when the population standard deviation is known, the confidence interval estimate is * + Zx/2 7 When the population standard deviation is unknown, the confidence interval estimate is * + tx/2 . The following table can be used: % Confidence Interval Za/2 0.1 90 1.64 0.05 95 1.96 0.01 99 2.58