Question

A set of chemistry exam scores are normally distributed with a mean of 70 points and a standard deviation of 4 points. Cam got a score of 65 points on the exam. What proportion of exam scores are higher than Cam's score? (hint the z score taken from the z score chart linked below will be the number of scores below Cam's. We are looking for the number of scores higher than Cam's Score. This is 1 - z score)

Answer 1

A set of chemistry exam scores are normally distributed with a mean of 70 points and a standard deviation of 4 points. Cam got a score of 65 points on the exam. What proportion of exam scores are higher than Cam's score? (hint the z score taken from the z score chart linked below will be the number of scores below Cam's. We are looking for the number of scores higher than Cam's Score. This is 1 - z score)

Answer 2

• 89.44%

Explanation:

Find the z-score:

• z = (x - μ) / σ
• z = (65 - 70) / 4 = -1.25

From the z-score table we get corresponding value of 0.1056

Proportion of scores higher than Cam's score:

• 1 - 0.1056 = 0.8944 = 89.44%