Many ?re stations handle emergency calls for medi- cal assistance as well as calls requesting ?re?ghting equip- ment. 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, calculate the probability that two successive calls will both be for medical assistance.
d. Still assuming independence, calculate the probability that for two successive calls, the ?rst is for medical assis- tance 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. The one call for medical assistance might be the ?rst call, or it might be the second call.)
f. Do you think that it is reasonable to assume that the requests made in successive calls are independent? Explain.