Mean (M) and coefficient of variation (CV expressed as a percentage) of different datasets are given in 1 to 4 below. Compute the standard deviation of each dataset and arrange in ascending order.

1.M = 60, CV = 70/3

2.M = 80, CV = 6.25

3.M = 70, CV = 160/7

4.M = 90, CV = 40/9

A4, 1, 2, 3

B1, 3, 4, 2

C4, 2, 1, 3 ✓ Correct

D2, 4, 3, 1

Correct answer: (C) 4, 2, 1, 3

Explanation

Standard deviation equals mean times coefficient of variation divided by hundred, so ordering the four datasets by SD gives 4, 2, 1, 3.

Dataset 4 has M 90 and CV 40/9 percent, giving SD 4.0, the smallest value.

Dataset 2 has M 80 and CV 6.25 percent, giving SD 5.0, the next larger.

Dataset 1 has M 60 and CV 70/3 percent, giving SD 14.0.

Dataset 3 has M 70 and CV 160/7 percent, giving SD 16.0, the largest.

Coefficient of variation is the ratio of standard deviation to mean expressed as a percentage.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.