What you’ll learn to do: Understand a chi-square goodness-of-fit test and interpret the conclusion in context

In the 1990s, type 2 diabetes was not as prevalent as it is today, and researchers suspect that it might be more prevalent in younger people than it used to be. Let’s say the ages of people were split into the following categories: young adult, middle-age adult, and older adult. To see if the proportion of adults in each age category is different now than it was in the 1990s, a chi-square hypothesis test could be done.