Gestation is the period of pregnancy from conception to deli

Gestation is the period of pregnancy from conception to delivery. Uncomplicated human gestations (without interventions) vary according to a national Normal distribution with mean 39 weeks and STD DEV = 2 weeks. If the rule is that +/- 2 is considered

Solution

z-score for two-tailed 95 % = 1.96

Let range be d weeks less or more than 39.

Z= (x-mu)/sigma= d/sigma

1.96 = d/2

d= 2*1.96 = 3.92 weeks

Range: ( 39-3.92, 39+3.92)

          = ( 35.08 , 42.92)