IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability that a random sample of 20 people have a mean IQ score greater than 110? (Round to 4 decimal places)

1 answer

Z = (score-mean)/SEm

SEm = SD/√n

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of that Z score.