Answer :
P(14 < X < 18) = P(X < 18) - P(X < 14) = P(z < (18 - 15)/2) - P(z < (14 - 15)/2) = P(z < 3/2) - P(z < -1/2) = P(z < 1.5) - [1 - P(z < 0.5)] = P(z < 1.5) + P(z < 0.5) - 1 = 0.93319 + 0.69146 - 1 = 1.62465 - 1 = 0.62465
Therefore, approximately 62.47% ofthe students are between 14 and 18 years old.
Therefore, approximately 62.47% ofthe students are between 14 and 18 years old.