Use the data from Exercise 9.35.

In exercise

The weights of four randomly and independently selected bags of potatoes labeled 20 pounds were found to be 21.0, 21.5, 20.5, and 21.2 pounds. Assume Normality.

a. Find a 95% confidence interval for the mean weight of all bags of potatoes.

b. Does the interval capture 20.0 pounds? Is there enough evidence to reject a mean weight of 20 pounds?

a. If you use the four-step procedure with a two-sided alternative hypothesis, should you be able to reject the hypothesis that the population mean is 20 pounds using a significance level of 0.05? Why or why not? The confidence interval is reported here: I am 95% confident that the population mean is between 20.4 and 21.7 pounds.

b. Now test the hypothesis that the population mean is not 20 pounds using the four-step procedure. Use a significance level of 0.05.

c. Choose one of the following conclusions:

i. We cannot reject a population mean of 20 pounds.

ii. We can reject a population mean of 20 pounds.

iii. The population mean is 21.05 pounds.