For patients aged 81 to 90 the probability is 090 that a cor

For patients aged 81 to 90, the probability is .090 that a coronary bypass patient will die soon after the surgery. (a) What is the expected number of operations until the first fatality? (Round your answer to 2 decimal places.) Expected number operations (b) What is the probability of conducting 18 or more operations before the first fatality? Hint: Use the CDF. (Round your answer to 4 decimal places.) Probability

Solution

this is a geometric distribution because we have a probability of succes of 0.090 when the patien will die soon after surgery

and the literal a) say that expected number of operations until the first fatality appear ( first success)

a) miu = 1 / 0.090 = 11.11 = 12

b) F ( 18 or more) = 1 - F ( 18) =

F(18) = 0.91^(18-1) * 0.090

F(18) = 0.018

F(18 or more ) = 1 - 0.018 = 0.9819