1. Chapter 9 Hypothesis Testing

5. Hypothesis Test Regarding a Population Variance or Standard Deviation
If a claim is made regarding the population variance or standard deviation, we can use the following steps to test the claim provided
(1) the sample is obtained using simple random sampling
(2) the population is normally distributed

6. Step 1: A claim is made regarding the population variance or standard deviation. The claim is used to determine the null and alternative hypothesis. We present the three cases for a claim regarding a population standard deviation.

9. Step 4: Compare the critical value with the test statistic.

10. Step 5: State the conclusion.

12. 351 360 358 356 359 358 355 361 352 EXAMPLE Hypothesis Testing
A can of 7-Up states that the contents of the can are 355 ml. A quality control engineer is worried that the filling machine is miscalibrated. In other words, she wants to make sure the machine is not under- or over-filling the cans. She randomly selects 9 cans of 7-Up and measures the contents. She obtains the following data.