IQ scores from the general population form a normal
distribution with a m = 100 and s = 15. However, data indicate that children’s
intelligence may be affected if their mothers have German measles during
pregnancy. Using hospital records, a
researcher obtained a sample of n = 25 school children whose mothers all had
German measles during their pregnancies.
The average IQ for this sample was x̅ = 94. Do these data indicate that German measles
have a significant effect on IQ? Test