posted by Gavin .
Using the central limit theorem, construct a 95% confidence interval for the average total cry time for infants in the control group and infants in the intervention group. For this question only, assume that the standard deviation of cry time within each group is known and is equal to 22 seconds.
95% = mean ± 1.96 SEm
SEm = SD/√n
What is your mean and n for each group?