A manufacturer of detergent claims that the contents of boxes sold weigh on average at least 30 ounces. The distribution of weights is known to be normal, with standard deviation 1.11. A random sample of 29 boxes yielded an average weight of 30.01 ounces. Suppose an inspector wants to test the null hypothesis that the population mean weight is at least 30 ounces. That is, test the null hypothesis

H

0

:?=30

H0:?=30

against the alternative hypothesis

H

1

:?

H1:?

Answer the following, rounding off your answers to two decimal places.

(a)What is the test statistic used in the decision rule?

(b)What is the critical value the inspector will use? Use a 10% level of significance.

(c)What decision do you make?

A.Do not reject the null hypothesis.

B.Reject the null hypothesis.

A manufacturer of detergent claims that the contents of boxes sold weigh on average at least 30 ounces. The distribution of weights is known to be normal, with standard deviation 1.11. A random sample of 29 boxes yielded an average weight of 30.01 ounces. Suppose an inspector wants to test the null hypothesis that the population mean weight is at least 30 ounces. That is, test the null hypothesis HDI=30 against the alternative hypothesis HIIIJ