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Confidence Interval For Effect Of Birth Weight On IQ Score

Please help with the following.

Confidence Interval for Effect of Birth Weight on IQ Score:

When investigating a relationship between birth weight and IQ, researchers found that 258 subjects with extremely low birth weights (less than 1000 g) had Wechsler IQ scores at age 8 with a mean of 95.5 and a standard deviation of 16.0. For 220 subjects with normal birth weights, the mean at age 8 is 104.9 and the standard deviation is 14.1. (Based on from "Neurobehavioral Outcomes of School-age Children Born Extremely Low Birth Weight or Very Preterm in the 1990s," by Anderson et al, Journal of the American Medical Association, Vol. 289, No. 24.)

Please construct a 95% confidence interval estimate of the difference between the mean I.Q. score of 8-year-old children born with low birth weight and the mean of 8-year-old children born with normal birth weight. Does IQ appear to be affected by birth weight? Why or why not?

Solution Summary

Step by step calculation of confidence interval and problem solution.