Knowing chi-square
Here, we will go over everything you need to know about chi-square for the exam and go over a practical example. Chi-square is another useful tool that every analyst should have in their toolbox. As with a t-test, this technically produces its own value called a chi-square statistic, but, again, we can get a p-value out of it, and that is all we practically need. There are two popular kinds of chi-square tests, and you may run into either one on the exam, so make sure you understand both:
- Chi-square goodness of fit
- Chi-square test for independence
Unlike t-tests, these two types do very different things. There is actually a third type—a chi-square test for homogeneity—but it is rarely used, and CompTIA decided not to add it to the exam. Let’s jump right in and get to what you need to know.
What you need to know about chi-square
A chi-square goodness of fit test is exactly what it sounds like: you are comparing a sample...
