Understanding hypothesis testing

In this section, we will cover what hypothesis testing is and why it is an important skill to have for a data analyst. Hypothesis testing is, in a nutshell, trying to guess whether or not your hypothesis is true. If someone asks you a specific business question, this is how you give a confident yes or no answer.

There are several different types of hypothesis tests, as you can imagine, but, for the purpose of this chapter, we are going to focus on one of the most common ones. The most common form of hypothesis testing is comparing two things and saying whether or not they are the same. It is as simple as that. Sometimes, you are comparing two completely separate things. Sometimes, you are comparing a “before” and “after” group. Often, you are comparing something altered to something unaltered. Which product sells better, A or B? Are our sales this year higher than last year? Would we sell the product to more women if we...