During the first 13 weeks of the television season, the Saturday evening 8:00 P.M. to 9:00 P.M. audience proportions were recorded as ABC 30%, CBS 26%, NBC 25%, and Independents 19%. A sample of 300 homes two weeks after a Saturday night schedule revision yielded the following viewing audience data: ABC 93 homes, CBS 60 homes, NBC 87 homes, and Independents 60 homes. Test with a=0.05 to determine whether the viewing audience proportions changed.