Response to the following question:
We wish to estimate the mean serum indirect bilirubin level of 4 day old infants. The mean for a sample of 160 infants was found to be 5.98 mg/100cc. Assume that the bilirubin levels of 4-day-old infants are approximately normally distributed with a standard deviation of 3.5mg/100cc. Construct a 95% confidence interval for the true mean bilirubin level in 4-day-old infants.