A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. Only 5% of the students taking the test scored higher than what grade?
A)70.04
B)67.96
C)55.48
D)82.52

Question

Quizplus · Accepted Answer

To find the grade above which only 5% of students scored, we need to find the z-score that corresponds to the 95th percentile of a standard normal distribution, which is approximately 1.645. Using the formula: Grade = Mean + (Z-score * Standard Deviation), we get: Grade = 69 + (1.645 * 9) = 82.805. The closest option is 82.52.

A Set of Final Examination Grades in a Calculus Course