In Telephone Interviews with a Random Sample of 1,100 Online

Multiple Choice

In telephone interviews with a random sample of 1,100 online shoppers, shoppers said they expected to spend an average of $976 for online purchases this year.Using a sample standard deviation of $180, you build a 95% confidence interval estimate of the average spending for the population of online shoppers represented by the sample and determine the margin of error for your 95% interval.Now suppose you want to reduce the margin of error in your interval by 20% without sacrificing the 95% confidence level.How big a sample would be required?

A) 1096
B) 1718
C) 1461
D) 1528
E) 1637