## A standardized test is given to a sixth grade class. Historically the mean score has been 173 with a variance of 30

A standardized test is given to a sixth grade class. Historically the mean score has been 173 with a variance of 30. The superintendent believes that the variance of performance may have recently increased. She randomly sampled 22 students and found a mean of 163 with a standard deviation of 5.9018. Is there evidence that the standard deviation has increased at the α=0.01 level?

State the hypotheses in terms of the standard deviation. Round the standard deviation to four decimal places when necessary.

b. Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places.

c. Determine the value of the test statistic. Round your answer to three decimal places.

d. Make the decision.

e. What is the conclusion?