(Solved): A standardued test is given to a sixth grade class. Historically the mean score has been 137 with a ...

A standardued test is given to a sixth grade class. Historically the mean score has been 137 with a standard devation of 23 . The superintendent believes that the standard deviation of performance msy have recently increased. She randomly sampled 22 -students and found a mean of 147 with a standard deviation of \( 25.6171 \), is there evidence that the standard deviation has increased at the \( a=0.005 \) leven Step 2 of 5 : Determine the critical value(s) of the test statistic if the fest is two-taled, separate the values with a cchnma. Round your answer ta three decimal places. Answer How to enter your ariswer (opens in new window) Keyboard Shortcuts