Chapter 12.4, Problem 25E

(a)

To determine

Thepercentage of births that occur after a gestation period of between $6$ and $7$ months, where the gestation period is approximately normally distributed with mean of $6$ months and standard deviation of $\frac{1}{2}$ months.

(b)

To determine

The percentage of births that occur after a gestation period of between $5$ and $6$ months, where the gestation period is approximately normally distributed with mean of $6$ months and standard deviation of $\frac{1}{2}$ months.