The ages of students in a school are normally distributed with a mean of 15 years and a standard deviation of 2 years. Approximately what percent of the students are between 14 and 18 years old?

a. 24.17%

b. 62.47%

c. 30.85%

d. 93.32%

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.