Question

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? Write your answer as a decimal rounded to 4 places.

Answer 1

Solution :

Given that ,

mean = = 268

standard deviation = = 15

P(x 300) = 1 - P(x   300)

= 1 - P((x - ) / (300 - 268) / 15)

= 1 -  P(z 2.13)  

= 1 - 0.9834

= 0.0166

Probability = 0.0166