Hypotheses and parameters. As in Exercise 3, for each of the following situations, define the parameter and write the null and alternative hypotheses in terms of parameter values.

a) Seat-belt compliance in Massachusetts was 65% in 2008.

The state wants to know if it has changed.

b) Last year, a survey found that 45% of the employees were willing to pay for on-site day care. The company wants to know if that has changed.

c) Regular card customers have a default rate of 6.7%. A credit card bank wants to know if that rate is different for their Gold card customers.

d) Regular card customers have been with the company for an average of 17.3 months. The credit card bank wants to know if their Gold card customers have been with the company on average the same amount of time.