Suppose that the gender of successive offspring in the same family are independent events and that the probability of a male or female offspring is .5. 1. What is the probability of two successive female off-spring? 2. What is the probability the exactly one of two successive children will be female? 3. Suppose that three successive offspring are male. What is the probability that a fourth child will be male?

A survey was performed among people 65 years of age and older who underwent open-heart surgery. It was found that 30% of patients died within 90 days of the operation, whereas an additional 25% of those who survived 90 days died within 5 years after the operation. 1. What is the probability that a patient undergoing open heart surgery will die within 5 years? 2. What is the mortality incidence (per patient month) in patients receiving this operation in the first 90 days after the operation? (assume that 90 days = 3 months.) 3. Answer the same question as in #2 for the period from 90 days to 5 years after the operation. 4. Can you tell if the operation prolongs life from the data presented? If not, then what additional data do you need?