All Exams Test series for 1 year @ ₹349 only
Question

Mean (M) and coefficient of variation (CV expressed as a percentage) of different datasets are given in A-D below. Compute the standard deviation of each dataset and arrange in ascending order.
A. M = 60, CV = 70/3
B. M = 80, CV = 6.25
C. M = 70, CV = 160/7
D. M = 90, CV = 40/9
Choose the correct answer from the options given below:

The correct answer is
D, B, A, C

Mean, CV, and Standard Deviation Relationship

This problem requires us to calculate the standard deviation for four different datasets (labeled A, B, C, and D). We are provided with the Mean ($M$) and the Coefficient of Variation ($CV$) for each dataset. Our final task is to arrange these datasets in ascending order based on their calculated standard deviations.

Standard Deviation Calculation Formula

The Coefficient of Variation ($CV$) is a measure of relative variability. It is defined as the ratio of the standard deviation ($SD$) to the mean ($M$), typically expressed as a percentage. The formula is:

$CV = \frac{SD}{M} \times 100\%$

To find the standard deviation ($SD$), we can rearrange this formula algebraically:

$SD = \frac{CV \times M}{100}$

We will use this rearranged formula to calculate the standard deviation for each dataset.

Calculate Standard Deviation for Each Dataset

Dataset A

For Dataset A, the Mean ($M$) is 60 and the Coefficient of Variation ($CV$) is $\frac{70}{3}\%$.

Using the formula $SD = \frac{CV \times M}{100}$, the Standard Deviation for Dataset A ($SD_A$) is calculated as:

$SD_A = \frac{(\frac{70}{3}) \times 60}{100} = \frac{70 \times 20}{100} = \frac{1400}{100} = 14$

Dataset B

For Dataset B, the Mean ($M$) is 80 and the Coefficient of Variation ($CV$) is $6.25\%$.

Using the formula, the Standard Deviation for Dataset B ($SD_B$) is calculated as:

$SD_B = \frac{6.25 \times 80}{100} = \frac{500}{100} = 5$

Dataset C

For Dataset C, the Mean ($M$) is 70 and the Coefficient of Variation ($CV$) is $\frac{160}{7}\%$.

Using the formula, the Standard Deviation for Dataset C ($SD_C$) is calculated as:

$SD_C = \frac{(\frac{160}{7}) \times 70}{100} = \frac{160 \times 10}{100} = \frac{1600}{100} = 16$

Dataset D

For Dataset D, the Mean ($M$) is 90 and the Coefficient of Variation ($CV$) is $\frac{40}{9}\%$.

Using the formula, the Standard Deviation for Dataset D ($SD_D$) is calculated as:

$SD_D = \frac{(\frac{40}{9}) \times 90}{100} = \frac{40 \times 10}{100} = \frac{400}{100} = 4$

Arrange Datasets by Standard Deviation

Let's summarize the calculated standard deviations for each dataset:

Summary of Standard Deviations
Dataset Mean (M) Coefficient of Variation (CV) Standard Deviation (SD)
A 60 $\frac{70}{3}\%$ 14
B 80 $6.25\%$ 5
C 70 $\frac{160}{7}\%$ 16
D 90 $\frac{40}{9}\%$ 4

Now, we need to arrange these datasets in ascending order based on their standard deviation values ($SD_D=4$, $SD_B=5$, $SD_A=14$, $SD_C=16$).

Comparing the values: $4 < 5 < 14 < 16$.

This order corresponds to the datasets D, B, A, and C.

Therefore, the correct arrangement of the datasets in ascending order of standard deviation is D, B, A, C.

Was this answer helpful?

Important Questions from Measures of Dispersion

  1. If for a moderately symmetrical distribution mean deviation is 12, then the value of standard deviation is

  2. Variance is independent of change of :

  3. Mean (M) and Standard Deviation (S) of different datasets are given in A-D below. Compute the coefficient of variation of each dataset and arrange in ascending order.
    A. M = 60, S = 14
    B. M = 70, S = 16
    C. M = 80, S = 5
    D. M = 90, S = 4
    Choose the correct answer from the options given below:
  4. Which of the following are methods of dispersion ?
    A. Median
    B. Mean
    C. Mean deviation
    D. Standard deviation
    E. Range
    Choose the correct answer from the options given below :
  5. When Mean deviation is divided by the average used in finding out the mean deviation itself, the resulting quantity is described as_____________.
    .

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App