Question

Mercury pollution is a serious ecological problem. It typically becomes dangerous once it falls into large bodies of water. At this point microorganisms change it into methylmercury (CH3203). The fish consume these microorganisms which makes them contaminated and hence anyone eating those fish are at risk.

Because of this, investigators are interested in research around mercury poisoning. In particular they want to investigate the methlymercury metabolism and whether it proceeds at a different rate for women than for men. The table below captures the half-life (in days) of an oral administration of protein-bound methlymercury among six females and nine males. Round all the numbers to 2 decimal places.

Methlymercury half-lives (in days)

Females

Males

52

72

69

88

73

87

88

74

87

78

56

70

78

93

74

Mean

70.83

79.33

Standard Deviation

15.09

8.08

a) (2 points) Create and interpret a 95% confidence interval for the average methylmercury half-life in males fish. Note: Do the calculations one time using R and the other time by hand.

b) (2 points) Create and interpret a 95% confidence interval for the average methylmercury half-life in females. Note: Do the calculations one time using R and the other time by hand.

c) (2 points) In comparing the confidence intervals created in (a) and (b) does there appear to be a difference in the average methylmercury half-life between males and females? Explain.

Answer 1

(c) Since the confidence intervals are overlapping, i.e., they have similar values within interval, we can say that there does not appear to be a significant difference in the average methyl mercury half-life between males and females.

22 s's ă = 79.33 s= la n=9 8.08, x=0.05, 8.08, 2=0.05, to tai2;ny = to.025;8 = 2.306. .:95%. el. ñ I tajn;nu. (11) = 6 79.33 + 3.306). (8-08) - [ 73.12, 85.54 (b) n=6, ã = 70,83, DE 15-09, 2= 0.05, tale; nya to.025;5 - 2.57) 954,01 70.63 + (2.571). (15.09)= [54,99, 86.67]. Scanned with