A/ B testing is a method used by businesses to test different designs and formats of a web page to determine if a new web page is more effective than a current web page. Web designers tested a new call to action button on its web page. Every visitor to the web page was randomly shown either the original call to action button (the control) or the new variation. The metric used to measure success was the download rate: the number of people who downloaded the file divided by the number of people who saw that particular callto action button. Results of the experiment yielded the following:

a. At the 0.05 level of significance, is there evidence of a difference in the download rate between the original call to action button and the new call to action button?

b. Find the p value in (a) and interpret its value.

c. Compare the results of (a) and (b) to those of Problem 10.31 on page 347.

Variations Downloads Visitors Original call-to-action button New call-to-action button 351 485 3,642 3.556