The article "Arsenic and Mercury in Lake Whitefish and Burbot Near the Abandoned Giant Mine on Great Slave Lake" (P. Cott, B. Zajdlik, et al., Journal of Great Lakes Research, 2016:223-232) presents measurements of arsenic concentrations in fish found in Northern Canada.

a. In a sample of 8 whitefish caught in Yellowknife Bay, the mean arsenic concentration in the liver was \(0.32 \mathrm{mg} / \mathrm{kg}\), with a standard deviation of \(0.05 \mathrm{mg} / \mathrm{kg}\). Find a \(95 \%\) confidence interval for the concentration in whitefish found in Yellowknife Bay.

b. In a sample of 8 whitefish caught in Baker Pond, the mean arsenic concentration in the liver was \(0.55 \mathrm{mg} / \mathrm{kg}\), with a standard deviation of \(0.36 \mathrm{mg} / \mathrm{kg}\). Should the Student's \(t\) distribution be used to find a 95\% confidence interval for the concentration in whitefish found in Baker Pond? If so, find the confidence interval. If not, explain why not.