22. ccn and actmedia provided a television channel targeted to individuals waiting in supermarket checkout lines. the channel showed news, short features, and advertisements. the length of the program was based on the assumption that the population mean time a shopper stands in a supermarket checkout line is 8 minutes. a sample of actual waiting times will be used to test this assumption and determine whether actual mean waiting time differs from this standard. anderson, david r.. essentials of statistics for business and economics (p. 409). south-western college pub. kindle edition.