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. 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 call-to-action button. Results of the experiment yielded the following table. Complete parts (a) and (b) below.

Variations	Downloads	Visitors
Original call-to-action button	330	3647
New call-to-action button	493	3560

a. At the =0.025 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? Let 1 represent the proportion of people shown the original call-to-action button, and let 2 represent the proportion of people shown the new call-to-action button. What are the null and alternative hypotheses to test?