1.97 Length of pregnancies.
The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with mean 266 days and standard deviation 16 days. Use the 68-95-99.7 rule to answer the following questions.
1.97
(a) 95% of pregnancies last between 234 and 298 days. (b) The shortest pregnancies are 234 days or less.