In a test quality of two television commercials, each commercial was shown is a separate rate test are six times over a one-week period. The following week a telephone survey was conducted to identify individuals who had seen the commercials. Those individuals were asked to state the primary message in the commercials. The following results were recorded.
                                                Commercial A    Commercial B
# Who Saw Commercial                     150                  200
#Who Recalled Commercial                 63                    60

a. Use a= .05 and test the hypothesis that there is no difference in the recall proportions for the two commercials.

b. Compute a 95% confidence interval for the difference between the recall proportions for the two populations.