2. A survey of 15 customers' satisfaction at a restaurant returns a sample mean customer satisfaction rating of 80 based on a scale of 0 to 100. The sample standard deviation is 6. a. Develop a 90% confidence interval estimate of the population mean customer satisfaction rating. What is the margin of error? b. Develop a 99% confidence interval estimate of the population mean customer satisfaction rating. What is the margin of error? c. Suppose the owner decides that surveying 15 people is not enough, so now he asks 41 customers. He finds the same sample mean of 80, and the same sample standard deviation of 6. Develop a 99% confidence interval estimate of the population mean customer satisfaction rating. What is the margin of error?