Question

The mean and standard deviations of two brands of watches are given below : [3] Brand-I Brand-II Mean : 36 months 48 months S.D. : 8 months 10 months Calculate coefficient of variation for the two brands and interpret the results.​

Answer 1

• Coefficient of variation is a measure of the dispersion of data points around the mean.
• The formula for the coefficient of variation is given by the ratio of standard deviation (σ) to mean (μ)

• Coefficient of variation = $\frac{standard deviation}{mean}$

Given - Mean of brand I (μ1)= 36 months

            Mean of brand II (μ2)= 48 months

            The standard deviation of brand I (σ1)= 8 months

            The standard deviation of brand II (σ2)= 10 months

To find -  Coefficient of variation for brand I (CV of Brand I)

               Coefficient of variation for brand II (CV of Brand II)

Solution - we use the formula mentioned above and we get,

              CV (Brand I) = σ1 / μ1

               $CV(Brand I) =\frac{8}{36}$

                                     =0.2222

              CV (Brand II) = σ2 / μ2

              $CV (Brand II) = \frac{10}{48}$

                                      = 0.2083

Hence, the coefficient of variation for the brand I is 0.2222 months and the coefficient of variation of brand II is 0.2083 months .