ages of all students enrolled at Casenec college form a normal distribution with a mean of 25 years and a standard deviation of 5 years.
a) What is the probability that a randomly selected student is between 19 and 28 years old?
b) What is the probability that a randomly selected student is at least 27.4 years?
c) What age is the boundary for the youngest 10%.?
d) What age is the boundary for the oldest 20% ?