How much money do people spend on graduation gifts? In

How much money do people spend on graduation gifts? In 2007, the National Retail Federation (www.nrf.com) surveyed 2,815 consumers who reported that they bought one or more graduation gifts that year. The sample was selected to be representative of adult Americans who purchased graduation gifts in 2007. For this sample, the mean amount spent per gift was $ 55.05. Suppose that the sample standard deviation was $ 20. Construct and interpret a 98% confidence interval for the mean amount of money spent per graduation gift in 2007.