What changes in a two-tailed test?
In the previous exercise, you rejected the null hypothesis. Suppose you set up the experiment differently before making this decision. Would that affect the outcome even if the data is the same?
Let's pretend you didn't know the outcome of the last exercise. Now you want to determine if the sample worker salary is equal to the population's. The NULL hypothesis operator changes to =
.
This means you are testing whether the sample average is statistically above or below the average. As a result, the experiement is testing in 2 directions from the mean, so it's a two-tailed test.
If you have a two-tailed test you must multiple the Z.TEST()
results by 2.
This exercise is part of the course
Introduction to Statistics in Google Sheets
Exercise instructions
- In
D9
once again perform aZ.TEST()
. - In
D10
, multiply the result by 2 to account for the second tail. - Determine the result of the hypothesis test in
D11
asREJECT
ofFAIL TO REJECT
.
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