This table lists the year$-$end prices and dividends of a stock and the annual returns of a risk$-$free asset:

Year Stock Price Stock Dividend Risk$-$free rate

$0$ $$20\mathrm{.}89--$

$1$ $$22\mathrm{.}83$ $$0\mathrm{.}622\mathrm{.}00\%$

$2$ $$26\mathrm{.}78$ $$0\mathrm{.}722\mathrm{.}50\%$

$3$ $$24\mathrm{.}12$ $$0\mathrm{.}841\mathrm{.}50\%$

$4$ $$25\mathrm{.}27$ $$0\mathrm{.}981\mathrm{.}30\%$

$5$ $$31\mathrm{.}93$ $$1\mathrm{.}252\mathrm{.}70\%$

a$)$ What is the arithmetic average return for the stock? What is the arithmetic average return for the risk$-$free asset?

b$)$ What is the risk premium of this stock?

c$)$ What are the variance and standard deviation of this stock?