Question Answered step-by-step Jordan is the manager of a used bookstore. He wants to estimate the average amount a customer spends per visit. A random sample of 90 customers’ receipts gave a mean of = = $6.90 with standard deviation o = $2.55. Find a 90% confidence interval for the average amount spent by all customers. Round each number in the interval to the nearest hundredth. . Previous Next *… Show more Math MATH 27.09710