Do social recommendations increase ad effectiveness? A study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. Data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. The results were:

a. Set up the null and alternative hypotheses to determine whether there is a difference in brand recall between viewers who arrived by following a social media recommendation and those who arrived by web browsing.
b. Conduct the hypothesis test defined in (a), using the 0.05 level of significance.
c. Compare the results of (a) and (b) to those of Problem 10.30 (a) and (b) on page 368.