A stock's returns have the following distribution:

Probability Rate of Return

$0\mathrm{.}1-2\%$

$0\mathrm{.}2-10\%$

$0\mathrm{.}410\%$

$0\mathrm{.}220\%$

$0\mathrm{.}130\%$

Calculate the stock's a$)$ expected return, b$)$ standard deviation, and c$)$ coefficient of variation.