Human pregnancies of healthy singleton fetuses (i.e., excluding pregnancies with early-term complications or miscarriages, and multiple births) are normally distributed with a mean of 266 days and a...

Human pregnancies of healthy singleton fetuses (i.e., excluding pregnancies with early-term complications or miscarriages, and multiple births) are normally distributed with a mean of 266 days and a standard deviation of 13 days.

1. What is the probability that a baby is born between 250 and 275 days?


2. If we stipulate that a baby is premature when born at least 3 weeks early, what is the probability a randomly selected baby is premature?


3. If we stipulate that a baby is overdue when born more than 2 weeks after the expected date, what is the probability a randomly selected baby is overdue?