This question is about an online business that is trying to test the design of its website. It has two designs for the website - A and B. Visitors to the website are randomly assigned one of the two designs. The firm wants to know which of the two designs generates a higher revenue per user. To do that we are going to use Design A as our control group and then compare Design B to find out if the revenue generated by Design B is significantly different from Design A. (By the way, this is called A/B testing in digital marketing language). As the Digital Marketing Executive, you need to test if the revenue generated by Design B is significantly different from Design A, at a 5% significance level. That is the main question: if the revenue generated by Design B is significantly different from Design A, at a 5% significance Level? You have to decide which test to use, depending upon whether you know the population standard deviation and your assumption of whether they are equal.
Write down the null and alternate hypotheses for this test:
What is your knowledge or assumption about the population standard deviation?