During the first 13 weeks of the t.v season the Saturday evening 8;00pm-9:00pm audience proportions were recorded as ABC 29% CBS 28% NBC 25% and independents 18%. a sample of 300 homes two weeks after Saturday night schedule revision yielded the following viewing audience data: ABC 95 homes CBS 70 homes NBC 89 homes and independent 46 homes .test a=.05 to determine whether the viewing audience proportions changed?