Performing a chi-squared test

In science and other disciplines, it's important to know if the variation you observe in your data is due to chance or is actually stemming from another source.

One way to understand this is with a chi-squared test, which you can conduct in Google Sheets using the CHITEST() function.

This function accepts two ranges. The first represents the observations, and the second represents the expected values.
In this case, both ranges must have the same COUNT() or the formula will fail. The formula returns the p-value you will use to determine whether or not to reject the null hypothesis.

CHITEST(observedRange, expectedRange)

In this exercise you are reviewing a call center agent's call times. The agent has a higher average call time than the expected call time for all other agents. Let's see if this agent's specific call times are due to chance, i.e. random call variation, or because the agent needs more training to speed up.