The mean age for a person getting married for the first time is 26.1 years. Assume the ages for first marriages are normal with a standard deviation of 4.7 years. (Give probability answers to four decimal places.)

a) What is the probability that a person being married for the first time is between 21.3 and 29.2 years old?

b) What is the probability that a person being married for the first time is over 28.6 years old?

c) What is the probability that a person being married for the first time is between 26.5 and 33.2 years old?

d) 90% of people getting married for the first time do so before what age?