Q.Find the coefficient of variation for the data: $8, 10, 12, 14, 16$.

Find the mean and standard deviation, then C.V. $= \dfrac{\sigma}{\bar{x}}\times100$.

Mean: $\bar{x} = \dfrac{8 + 10 + 12 + 14 + 16}{5} = \dfrac{60}{5} = 12$.

Standard deviation: squared deviations from $12$ are $16, 4, 0, 4, 16$, summing to $40$, so

Coefficient of variation:

$\text{C.V.} = \frac{\sigma}{\bar{x}}\times 100 = \frac{2.83}{12}\times 100 \approx 23.57\%.$ …

Leaving the answer as the ratio $\dfrac{\sigma}{\bar{x}} \approx 0.236$ without multiplying by $100$ — the coefficient of variation is conventionally quote …