The Hunter Family Corporation owns roadside diners in numerous locations across the country. For the past few months, the company has undertaken a new advertising study. Initially, company executives selected 22 of its retail outlets that were similar with respect to sales volume, profitability, location, climate, economic status of customers, and experience of store management. Each of the outlets was randomly assigned one of two advertising plans promoting a new sandwich product. The accompanying data represent the number of new sandwiches sold during the specific test period at each retail outlet.

Hunter executives want you to determine which of the two advertising plans leads to the largest average sales levels for the new product. They are not willing to make the assumptions necessary for you to use the t-test. They do not wish to have an error rate of more than 0.05.

Advertising Plan 1 ($) Advertising Plan 2 ($)
1,711 2,100 1,915 2,210 1,905 1,950 2,153 3,004 1,504 2,725 1,195 2,619 2,103 2,483 1,601 2,520 1,580 1,904 1,475 1,875 1,588 1,943