
Answer:
(a) Sample A: mean = 6, sd = 1.63
Sample B: mean = 65, sd = 1.63
Sample C: mean = 1,012, sd = 1.63
(b) The idea is to illustrate that the standard deviation is a function of the value of the mean.
Step-by-step explanation:
(a) Sample A: 4, 6, 8
Mean = (4+6+8)/3 = 18/3 = 6
Standard deviation = sqrt[((4-6)^2 + (6-6)^2 + (8-6)^2) ÷ 3] = sqrt(8 ÷ 3) = sqrt(2.667) = 1.63
Sample B: 63, 65, 67
Mean = (63+65+67)/3 = 195/3 = 65
Standard deviation = sqrt[((63-65)^2 + (65-65)^2 + (67-65)^2) ÷ 3] = sqrt(8 ÷ 3) = sqrt(2.667) = 1.63
Sample C: 1,010, 1,012, 1,014
Mean = (1,010+1,012+1,014)/3 = 3,036/3 = 1,012
Standard deviation = sqrt[((1,010-1012)^2 + (1,012-1,012)^2 + (1,014-1,012)^2) ÷ 3] = sqrt(8 ÷ 3) = sqrt(2.667) = 1.63
(b) The exercise shows that the standard deviation is a function of the value of the mean.