Many fire stations handle emergency calls for medical assistance as well as calls requesting firefighting equipment. A particular station says that the probability that an incoming call is for medical assistance is .85. This can be expressed as P(call is for medical assistance) .85.

a. Give a relative frequency interpretation of the given probability.

b. What is the probability that a call is not for medical assistance?

c. Assuming that successive calls are independent of one another (i.e., knowing that one call is for medical assistance doesn’t influence our assessment of the probability that the next call will be for medical assistance), calculate the probability that both of two successive calls will be for medical assistance.

d. Still assuming independence, calculate the probability that for two successive calls, the first is for medical assistance and the second is not for medical assistance.

e. Still assuming independence, calculate the probability that exactly one of the next two calls will be for medical assistance. (Hint: There are two different possibilities that you should consider. The one call for medical assistance might be the first call, or it might be the second call.)

f. Do you think it is reasonable to assume that the requests made in successive calls are independent?

Explain.