Include all workings.

b. A bank is testing a new method for getting delinquent customers to pay their past due

credit card bills. The standard way was to send a letter (costing $0.40 each) asking the

customer to pay. That worked 30% of the time. They want to test a new method that

involves sending a video tape to the customer encouraging them to contact the bank

and set up a payment plan. Developing and sending the video costs about $10.00 per

customer. What is the parameter of interest? What are the null and alternate hypotheses?

c. The bank sets up an experiment to test the effectiveness of the video tape. They mail it

out to several randomly selected delinquent customers and keep track of how many

actually do contact the bank to arrange payments. The banks statistician calculates the

P-value of 0.003. What does this p-value suggest about the video tape?

d. The statistician tells the ban's management that the results are clear and that they should

switch to the video tape method. Do you agree? What else may you also wish to know?