A school administrator claims that the standard deviation for eighth-grade students on a U.S. history assessment test is greater than 30 points. A random sample of 18 eighth-grade students has a standard deviation of 30.6 points. At α = 0.01, is there enough evidence to support the administrator’s claim?
(a) Identify the claim and state H0 and Ha,
(b) Find the critical value(s) and identify the rejection region(s),
(c) Find the standardized test statistic X2,
(d) Decide whether to reject or fail to reject the null hypothesis,
(e) Interpret the decision in the context of the original claim. Assume the population is normally distributed.