23. What is the effect of better maternal care on gestation time and preemies?

The goal is to obtain pregnancies 240 days (8 months) or longer. Suppose the distribution of gestation time for pregnancy mothers with vitamins only follows normal distribution with mean of 250 days and standard deviation of 20 days . And the distribution of gestation time for pregnancy mothers with vitamins and better food follows normal distribution with mean of 266 days and standard deviation of 15 days .

a)Among mothers with vitamins only, what percent of mothers failed to carry their babies at least 240 days?

b)Among mothers with vitamins and better food, what percent of mothers failed to carry their babies at least 240 days?