For these questions, the data set is given at this text's website. Assume that the data sets are from random samples and the distributions are Normal.
a. Find a 95% confidence interval for the difference between means, state whether it captures 0, and explain what that shows about the means.
b. Perform a hypothesis test to see whether the means are significantly different using a significance level of 0.05. Explain your conclusion clearly.
Navy Commissary Prices Amber Sanchez, a statistics student, collected data on the prices of the same items at the Navy commissary on the naval base in Ventura County, California, and a nearby Kmart.
The items were matched for content, manufacturer, and size and were priced separately.
a. Report and compare the sample means.
b. Assume that they are a random sample of items, and use a significance level of 0.05 to test the hypothesis that the Navy commissary has a lower mean price.
Assume that the population distribution of differences is approximately Normal.