Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma. Over a period of months, an adult male patient has taken five blood tests for uric acid. The mean concentration was x = 5.27 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with = 1.87 mg/dl.

Find the sample size necessary for a 95% confidence level with maximal margin of error E = 1.18 for the mean concentration of uric acid in this patient's blood. (Round your answer up to the nearest whole number.)