Have you ever wondered if lottery numbers were evenly distributed or if some numbers
occurred with a greater frequency? How about if the types of movies people preferred
were different across different age groups? What about if a coffee machine was
dispensing approximately the same amount of coffee each time? You could answer these
questions by conducting a hypothesis test.

You will now study a new distribution, one that is used to determine the answers to the
above examples. This distribution is called the Chi-square distribution.

In this chapter, you will learn the three major applications of the Chi-square distribution:

- The goodness-of-fit test, which determines if data fit a particular distribution, such as
with the lottery example
- The test of independence, which determines if events are independent, such as with
the movie example
- The test of a single variance, which tests variability, such as with the coffee example

Though the Chi-square calculations depend on calculators or computers for most of the
calculations, there is a table available (see the Table of Contents *15. Tables*). TI-83+ and TI-84 calculator instructions are included in the text.