The Chi-Square test for proportions is illustrated using the following example.
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 29%, CBS 28%, NBC 25%, and independents 18%. A sample of 300 homes two weeks after a Saturday night schedule revision yielded the following viewing audience data: ABC 95 homes, CBS 70 homes, NBC 89 homes, and independents 46 homes.
Test with a= 0.05 to determine whether the viewing audience proportions changed.© BrainMass Inc. brainmass.com June 4, 2020, 3:00 am ad1c9bdddf
Please see the attachments for the complete solution.
The Chi-Square test for proportions is illustrated using the p-value approach and traditional approach.
The null and alternative hypotheses are
H0: pABC = 0.29, pCBS = 0.28, pNBC = 0.25, pIND = 0.18
Ha: The proportions are not pABC = 0.29, pCBS = 0.28, pNBC = 0.25, pIND = 0.18
The test statistic is given by,
(please see ...
In this solution a chi-square test is used to determine whether there was a change in proportions.