It is crucial that the variance of a production process be less than or equal to 25. A sample of 22 is taken. The sample variance equaled 26.
a. Develop a 90% confidence interval for the population variance.
b. Develop a 90% confidence interval for the population standard deviation.
c. Describe the null and alternative hypotheses to be tested.
d. Calculate the test statistic.
e. The null hypothesis is to be tested at 10% level of significance. Using critical value approach, describe the decision rule for the test.
f. What do you conclude about the population variance?