The recession has caused many people to use their credit cards far less. In fact, in the United States, 60% of consumers say they are committed to living with fewer credit cards. A sample of n = 400 consumers with credit cards are randomly selected.
a. What is the average number of consumers in the sample who said they are committed to living with fewer credit cards?
b. What is the standard deviation of the number in the sample who said they are committed to living with fewer credit cards?
c. Within what range would you expect to find the number in the sample who said they are committed to living with fewer credit cards?
d. If only 200 of the sample of consumers said they were committed to living with fewer credit cards, would you consider this unusual? Explain. What conclusion might you draw from this sample information?