Answer:
0.5466
Explanation:
Given that 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.
Let X be the length of pregnancies
X is N(266,16)
To find out the probability that pregnancies last between 240 and 270 days (roughly between 8 months and 9 months)
P(240<x<270)
convert each into Z score as

x=240 means Z = -1.625
x=270 means z=0.25
Required prob
=
