The waiting time to place an order in a fast-food restaurant is normally distribute with unknown population standard deviation. The sample mean and sample sta deviation are 5.1 minutes and 1.5 minutes from a sample of 25 orders. It is give 99% confidence interval of the population mean waiting time to place an order i between a and b. What is the margin of error of the 99% confidence interval of population mean waiting time to place an order? Hints: when the population standard deviation is known, the confidence interva estimate is * + Za/2 Vm When the population standard deviation is unknown, the confidence inte estimate is * + tx/2 mil The following table can be used: Degree of % Confidence Interval freedom to z 0.1 90 24 1.711 D.05 95 24 2.064 0.01 99 24 2.797