Suppose that the mean weight of newborn babies is normally distributed with a mean of 6.9...

Suppose that the mean weight of newborn babies is normally distributed with a mean of 6.9 pounds and a standard deviation of 0.8 pound. A developmental psychologist wants to test whether newborn babies of mothers who use drugs during pregnancy differ in weight from the average baby. The psychologist takes a random sample of 30 mothers who used drugs during pregnancy and computes the mean birth weight of these mothers’ babies. This sample of 30 mothers has a sample mean of 6.7 pounds. Using an alpha level of .01, test whether mothers’ drug use during pregnancy affects newborn babies’ birth weight. Which of the following is the most accurate mathematical null hypothesis?

A) μ < 6.7

B) μ ≠ 6.7

C) μ ≠ 0

D) μ = 6.9

Expert Solution

orchestra answered 1 year ago

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