To maintain high consistency in its manual sewing operations, a custom manufacturer of high-quality fashion clothing has a goal in which all sewing employees should score within a standard deviation of 9 on a sewing dexterity test. To test adherence to this goal, a random sample of 30 employees was subjected to a needle-board dexterity test.
a. State the hypotheses to test whether the standard deviation of the dexterity test scores exceeds 9.
b. Calculate the value of the test statistic. Assume that dexterity scores are normally distributed.
c. Use Excel's function (CHISQ.DIST.RT or CHISQ.DIST) to compute the p-value.
d. Make a conclusion at each of the following significance levels: 1%, 5%, and 10%.