From the book p 423-5

2. Credit Card Debt It has been reported that the average credit card debt for college seniors is $3262. The student senate at a large university feels that their seniors have a debt much less than this, so it conducts a study of 50 randomly selected seniors and finds that the average debt is $2995, and the population standard deviation is $1100. With a significance level of 0.05, is the student senate correct?

4. Salaries of Ph.D. Students Full-time Ph.D. students receive an average salary of $12,837 according to the U.S. Department of Education. The dean of graduate studies at a large state university feels that Ph.D. students in his state earn more than this. He surveys 44 randomly selected students and finds their average salary is $14,445, and the population standard deviation is $1500. With an alpha of 0.05, is the dean correct?

16. Soft Drink Consumption A researcher claims that the yearly consumption of soft drinks per person is 55 gallons. In a sample of 50  randomly selected people, the mean of the yearly consumption was 56.3 gallons. The standard deviation of the population is 3.5 gallons. Find the P-value for the test. On the basis of the P-value, is the researcher’s claim valid?