High School

Calculate the Coefficient of Variation for the following data:

Heights: 160, 170, 164, 163, 164, 163, 162, 163, 161, 160

(Ans. 1.67%)

Answer :

To calculate the Coefficient of Variation (CV) for the given data, we need to follow these steps:

  1. Calculate the Mean of the Data:

    The mean is the average of all the data points.

    [tex]\text{Mean} = \frac{160 + 170 + 164 + 163 + 164 + 163 + 162 + 163 + 161 + 160}{10} = \frac{1630}{10} = 163[/tex]

  2. Calculate the Standard Deviation (SD) of the Data:

    The standard deviation measures how much the data points tend to deviate from the mean.

    First, calculate the sum of the squared deviations from the mean:

    [tex]\begin{align*}
    & (160 - 163)^2 + (170 - 163)^2 + (164 - 163)^2 + (163 - 163)^2 + (164 - 163)^2 \\
    & + (163 - 163)^2 + (162 - 163)^2 + (163 - 163)^2 + (161 - 163)^2 + (160 - 163)^2
    \end{align*}[/tex]

    Which equals:

    [tex]9 + 49 + 1 + 0 + 1 + 0 + 1 + 0 + 4 + 9 = 74[/tex]

    Now divide by the number of data points to get the variance, and then take the square root for the standard deviation:

    [tex]\text{Variance} = \frac{74}{10} = 7.4[/tex]

    [tex]\text{Standard Deviation} = \sqrt{7.4} \approx 2.72[/tex]

  3. Calculate the Coefficient of Variation (CV):

    The coefficient of variation is the ratio of the standard deviation to the mean, expressed as a percentage:

    [tex]\text{CV} = \left( \frac{\text{Standard Deviation}}{\text{Mean}} \right) \times 100\%[/tex]

    [tex]\text{CV} = \left( \frac{2.72}{163} \right) \times 100\% \approx 1.67\%[/tex]

Therefore, the Coefficient of Variation for the given data is approximately 1.67%.