Understanding Basic Statistics 6th Edition by Charles Henry Brase,Corrinne Pellillo Brase

Exercise 31

Marketing: Shopping Time How much customers buy is a direct result of how much time they spend in a store. A study of average shopping times in a large national houseware store gave the following information (Source: Why We Buy: The Science of Shopping by P. Underhill).
Women with female companion: 8.3 min.
Women with male companion: 4.5 min.
Suppose you want to set up a statistical test to challenge the claim that a woman with a female friend spends an average of 8.3 minutes shopping in such a store.
(a) What would you use for the null and alternate hypotheses if you believe the average shopping time is less than 8.3 minutes Is this a right-tailed, left-tailed, or two-tailed test
(b) What would you use for the null and alternate hypotheses if you believe the average shopping time is different from 8.3 minutes Is this a right-tailed, left-tailed, or two-tailed test
Stores that sell mainly to women should figure out a way to engage the interest of men-perhaps comfortable seats and a big TV with sports programs. Suppose such an entertainment center was installed and you now wish to challenge the claim that a woman with a male friend spends only 4.5 minutes shopping in a houseware store.
(c) What would you use for the null and alternate hypotheses if you believe the average shopping time is more than 4.5 minutes Is this a right-tailed, left-tailed, or two-tailed test
(d) What would you use for the null and alternate hypotheses if you believe the average shopping time is different from 4.5 minutes Is this a right-tailed, left-tailed, or two-tailed test