Chapter 5.9, Problem 124E

The typical cost of damages caused by a fire in a family home is $20,000. Comparable costs for an apartment fire and for fire in other dwelling types are $10,000 and $2000, respectively. If four fires are independently reported, use the information in Exercise 5.123 to find the

a expected total damage cost.

b variance of the total damage cost

5.123 The National Fire Incident Reporting Service stated that, among residential fires, 73% are in family homes, 20%are in apartments, and 7%are in other types of dwellings. If four residential fires are independently reported on a single day, what is the probability that two are in family homes, one is in an apartment, and one is in another type of dwelling?