15. Life Insurance in Force. The American Council of Life Insur-
ers provides information about life insurance in force per covered
family in the Life Insurers Fact Book. Assume that the standard devi-
ation of life insurance in force is $50,900.
a. Determine the probability that the sampling error made in estimat-
ing the population mean life insurance in force by that of a sample
of 500 covered families will be $2000 or less.
b. Must you assume that life-insurance amounts are normally dis-
tributed in order to answer part (a)? What if the sample size is 20
instead of 500?
c. Repeat part (a) for a sample size of 5000.
