The average age for a person getting married for the first time is 26 years (U.S. News and World Report, June 6, 1994). Assume the ages for first marriages have a normal distribution with a standard deviation of four years.
a) What is the probability that a person getting married for the first time is younger than 23 years of age?
b) What is the probability that a person getting married for the first time is in his or her twenties?