5a) A sample of size 22 was taken in an experiment on tensile adhesion. The mean load at specimen failure for this sample was 11.8 megapascals and standard deviation was 2.78 megapascales. If the population is known to be approximately normal, what is a 95% confidence interval on the population mean? a. (11.47, 12.53) b. (9.63, 14.21) c. (10.57, 13.03) d. (12.67, 15.13) 5b) Given that a researcher wants to investigate the mercury contamination in a certain species of fish in a lake. A sample of 53 fish was taken, and the mean mercury concentration found was 0.525 with standard deviation 0.349. A 95% confidence interval would be: a. (0.342, 0.915) b. (0.527, 0.663) c. Conditions are not satisfied, so a confidence interval can't be constructed d. (0.431, 0.619)