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:
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.
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.
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:
$SD_A = \frac{(\frac{70}{3}) \times 60}{100} = \frac{70 \times 20}{100} = \frac{1400}{100} = 14$
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:
$SD_B = \frac{6.25 \times 80}{100} = \frac{500}{100} = 5$
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:
$SD_C = \frac{(\frac{160}{7}) \times 70}{100} = \frac{160 \times 10}{100} = \frac{1600}{100} = 16$
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:
$SD_D = \frac{(\frac{40}{9}) \times 90}{100} = \frac{40 \times 10}{100} = \frac{400}{100} = 4$
Let's summarize the calculated standard deviations for each dataset:
| 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.
If for a moderately symmetrical distribution mean deviation is 12, then the value of standard deviation is
Variance is independent of change of :
When Mean deviation is divided by the average used in finding out the mean deviation itself, the resulting quantity is described as_____________.
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