Question

Mr. Barnett’s test is normally distributed with a mean of 65 with a standard deviation of five points what is the probability that a randomly selected score is greater than 75 points

Answer 1

Answer: 2.5%

Explanation:

Mean score = 65

Standard deviation = 5

Score (x) = >75

Z-score = [(score - mean) ÷ standard deviation]

Z - score = [(75 - 65) ÷ 5]

Z - score = 10 ÷ 5 = 2

P(score higher than 75) = 100 - 95 = 5/2 = 2.5%