Question

1. Pregancy length in humans is Normally distributed with mean 266 days and standard deviation 16 days.

(a) Find the probability that a pregnancy lasts more than 280 days.

(b) Find the probability that a pregnancy lasts less than 37 weeks.

(c) Find the probability that a pregnancy lasts between 250 and 270 days.

(d) If the pregancy will be induced at the 290th day, what is the probability that the birth will happen between 266 days and the induction day?

(e) Find the probability that a birth will happen within the next week if the baby has not arrived at 280 days.

(f) The population interquartile range is defined as the difference between the 25th and 75th percentiles of the distribution of pregnancy lengths. Find its value. (g) If the pregnancy is considered to be late if it is among the 5% longest of all pregancies, how long does a pregnancy have to be before it is considered to be late?

Answer 1