When not interrupted artificially the gestation periods for

When not interrupted artificially, the gestation periods for human fetuses approximate a normal curve with a mean of 270 days and a standard deviation of 15 days. What proportion of gestation periods will be between 245 and 255 day

Solution

mu = 270

std dev = 15

P(245<x<255) = P(-1<z<1)

=0.6824