During a one-week experiment, motion was added to in-store sales displays at a random sample of your firm’s stores nationwide. The resulting sales increases for these products (compared to the week before) averaged $441.84, with a standard deviation of $68.91. There were 18 stores participating in the experiment.16
a. Find the 95% confidence interval for the population mean sales increase.
b. Complete the following sentence: We are 95% confident that the population mean sales increase is at least ______________________.
c. The manager of one of your firm’s stores would like to assess the possible sales increases. This store was not part of the survey. Assuming conditions are similar to those of the experiment, complete the following sentence: We are 95% sure that the one-week savings for this store when motion is added will be between ____________________ and ____________________.