The date of births in humans is approximately normally distributed with a mean at 280 days gestation (this is the so-called "due date") and a standard deviation of 8 days. Suppose that a pregnant woman will have a scheduled cesarean section to deliver her baby.
Determine how many days before the due date the cesarean section should be carried out so that there is no more than a 10 percent chance that the woman will go into labor before that date.