A company offers a cloud-sharing service aimed at consumers, including a free level of service to all, as well as higher paying levels. Currently, they offer a relatively low level of free service hoping that people will readily see the need for a higher fee-based level. It decides to run an experiment, offering to some extent a higher level of free service hoping that more people will become engaged users and will upgrade. For several weeks, customers are offered either “low” or “high” levels of service, on a random basis, and then the number of upgrades over the next 3 months is tracked. Here are the results:

(a) Calculate the difference between the two conversion rates

(b) Specify a resampling procedure to test whether the difference in the conversion rates might have arisen by chance