In a test of quality of two television commercials, each commercial was shown in separate test area six times over one-week period. The following week telephone survey was conducted to determine individuals who had seen the commercials. Those individuals were asked to describe the primary message in the commercials. The following results were recorded.
Commercial A: 150 people saw commercial, 63 people recalled the message
Commercial B: 200 people saw commercial, 60 people recalled the message
Use? = .05 and test the hypothesis that there is no difference in recall proportions for two commercials.
a. Test statistic =
b. p-value =
c. Calculate a 95% confidence interval for the population proportion who recalled Commercial A minus the population proportion for Commercial B.