A variable is normally distributed with a hypothesized population mean of 20 and a standard deviation of 4. What percentage of scores are greater than 23?
A) 77.34%
B) 75.00%
C) 27.34%
D) 22.66%

Question

Quizplus · Accepted Answer

To find the percentage of scores greater than 23 in a normally distributed variable with a mean of 20 and a standard deviation of 4, we calculate the z-score for 23. The z-score is (23 - 20) / 4 = 0.75. Looking up 0.75 on the standard normal distribution table or using a calculator, we find that approximately 77.34% of scores are below 23, leaving about 22.66% of scores above 23.

A Variable Is Normally Distributed with a Hypothesized Population Mean