A strategy called A/B testing is being implemented by many e-commerce firms. A product web page is modified by adding a picture or other visual change. Then, a fraction of the traffic is routed to the new page. For a sample of 1000 consumers who visit the original page, 70 purchase the item. From a sample of 400 customers who visit the modified site, 42 purchase the item.
(a) Construct a two-way table based on these frequencies.
(b) Formulate the null hypothesis.
(c) Conduct a χ² test of your null hypothesis. Use α = .05 .
(d) Comment on the form of any departure from the null hypothesis.