Acetaminophen is an active ingredient found in more than 600 over-the-counter and prescription medicines, such as pain relievers, cough suppressants, and cold medications. It is safe and effective when used correctly, but taking too much can lead to liver damage.

Source: http://www.keepkidshealthy.com/medicine_ cabinet/acetaminophen.html A researcher believes the amount of acetaminophen in a particular brand of cold tablets contains a mean amount of acetaminophen per tablet different from the 600 mg claimed by the manufacturer.

A random sample of 30 tablets had a mean acetaminophen content of 596.3 mg with a standard deviation of 4.7 mg.

a. Is the assumption of normality reasonable? Explain.

b. Construct a 99% confidence interval for the estimate of the mean acetaminophen content.

c. What does the confidence interval found in part b suggest about the mean acetaminophen content of one pill? Do you believe there is 600 mg per tablet? Explain.