Question

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 eight blood tests for uric acid. The mean concentration was x bar = 5.35 mg/dl. The distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.85 mg/dl.

A. Construct a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. Interpret.

B. Find the sample size necessary for a 95% confidence level with maximal margin of error E = 1.10 for the mean concentration of uric acid in this patient's blood.

Answer 1

a)

95% confidence interval for the population mean concentration of uric acid=4.068 ; 6.632

there is 955 confidence that population mean concentration of uric acid will fall between 4.068 and 6.632.

b)

for 95 % CI value of z=	1.960
standard deviation σ=	1.85
margin of error E =	1.1
required sample size n=(zσ/E)2                                         =	11.0