Suppose we want to estimate the concentration (μg/mL) of a specific dose of ampicillin in the urine after various pe- riods of time. We recruit 25 volunteers who have received ampicillin and find they...

Suppose we want to estimate the concentration (μg/mL)

of a specific dose of ampicillin in the urine after various pe-
riods of time. We recruit 25 volunteers who have received

ampicillin and find they have a mean concentration of 7.0
μg/mL with a standard deviation of 2.0 μg/mL. Assume
the underlying population distribution of concentrations is
normally distributed.
Problem a) Find a 95% CI for the population mean concentration.
Problem b) Find a 99% CI for the population variance of the
concentrations.
Problem c) How large a sample would be needed to ensure
that the length of the CI in Problem a is 0.5 μg/mL
assuming the sample standard deviation remains at
2.0 μg/mL?