The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample is between 98 and 103?
A) 0.3264
B) 0.9428
C) 0.4702
D) 0.7471

Question

Quizplus · Accepted Answer

The standard error of the mean for a sample of 50 is 15/sqrt(50). Using the standard normal distribution, the probability that the sample mean is between 98 and 103 is approximately 0.7471.

The Intelligence Quotient (IQ) Test Scores for Adults Are Normally