## Question 423:

the lengths of human pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. What is the probability that a pregnancy lasts at least 300 days?If you need help with the concepts covered in this question (like z-scores and the normal-curve) you can download a visual and easy to understand Crash Course in Z-scores and an Excel Calculator which will do everything you need to do with z-scores.