Baby weights: According to a recent National Health Statistics Reports, the weight of male babies less than 2 months old in the United States is normally distributed with mean 11.5 pounds and standard...

Baby weights:
According to a recent National Health Statistics Reports, the weight of male babies less than 2 months old in the United States is normally distributed with mean 11.5 pounds and standard deviation 2.7 pounds.

a. What proportion of babies weigh more than 13 pounds?

b. What proportion of babies weigh less than 15 pounds?

c. What proportion of babies weigh between 10 and 14 pounds?

d. Is it unusual for a baby to weigh more than 17 pounds?