Question:

On a physical science test the scores of a random sample of 22 eighth grade students have a standard deviation of 27.7. This result prompts a test administrator to claim that the standard deviation for eighth graders on the exam is less than 29. At a= 0.10, is there enough evidence to support the administrator’s claim?

a) Write the claim mathematically and identify Ho and Ha.

b) find the critical value(s) and identify the rejection region

c) use the X2 test to find the standardized test statistic

d) decide whether to reject or fail to reject the null hypothesis

e) interpret the decision in the context of the original claim