In a study aimed at reducing developmental problems in low-birth-weight (under 2500 grams) babies, 347 infants were exposed to a special educational curriculum while 561 did not receive any special help.

After 3 years the children exposed to the special curriculum showed a mean IQ of 93.5 with a standard deviation of 19.1; the other children had a mean IQ of 84.5 with a standard deviation of 19.9. Find a 95% confidence interval estimate for the difference in mean IQs of low-birth-weight babies who receive special intervention and those who do not.

89.039.0

9.02.60

9.04.42

9.06.24

89.019.5