An April 15, 2002 report in Time Magazine stated that the average age for women to marry in the U.S. is now 24 years of age. If the standard deviation is assumed to be 5 years, find the probability that a random sample of 31 U.S. women would show a mean age at marriage of less than or equal to 22.7 years. (Answer to four decimal places) I'm looking for a well explained answer.