The coefficients of variation of two distributions are $60$ and $70$,and their standard deviations are $21$ and $16$,respectively. What are their arithmetic means?

The formula for the coefficient of variation $(C.V.)$ is given by $C.V. = \frac{\sigma}{\bar{x}} \times 100$,where $\sigma$ is the standard deviation and $\bar{x}$ is the arithmetic mean.
For the first distribution:
$C.V._{1} = 60$,$\sigma_{1} = 21$
$60 = \frac{21}{\bar{x}_{1}} \times 100$
$\bar{x}_{1} = \frac{21 \times 100}{60} = \frac{2100}{60} = 35$
For the second distribution:
$C.V._{2} = 70$,$\sigma_{2} = 16$
$70 = \frac{16}{\bar{x}_{2}} \times 100$
$\bar{x}_{2} = \frac{16 \times 100}{70} = \frac{1600}{70} \approx 22.86$
Thus,the arithmetic means are $35$ and $22.86$ respectively.