Question

The Coefficients of variation of two series are 30% and 25% and their standard deviations are 15 and 9 respectIvely. Find their means.

Answer 1

First Series:

Coefficient of variation: 30%

s = 15

x̄ = ?

Coefficient of variation = \(\frac{s}{\bar x}\) × 100

∴ 30 = \(\frac{15}{\bar x}\) × 100

∴ 30x̄ = 1500

∴ x̄ = \(\frac{1500}{30}\)

∴x̄ = 50

Second series:

Coefficient of variation: 25%

s = 9

x̄ = ?

Coefficient of variation = \(\frac{s}{\bar x}\) × 100

∴ 25 = \(\frac{9}{\bar x}\) × 100

∴ 25x̄ = 900

∴ x̄ = \(\frac{900}{25}\)

∴x̄ = 36