llll$.4.$ The following table shows the rate of returns for large company stocks and Treasury bills $($T$-$bills$)$ for year $1970$ through $1975$:

Year Large co$.$ stock return T$-$bill return

$19703\mathrm{.}94\%6\mathrm{.}50\%$

$197114\mathrm{.}304\mathrm{.}36$

$197218\mathrm{.}994\mathrm{.}23$

$197314\mathrm{.}697\mathrm{.}29$

$197426\mathrm{.}477\mathrm{.}99$

$197537\mathrm{.}235\mathrm{.}87$

$(1)$ Please calc ulate the risk premium in each year for the large$-$company stocks versus the T$-$bills.

$(2)$ What was the arithmetic average risk premium over this period? What was the standard deviation of the risk premium over this period?

$(3)$ Is it possible for the risk premium to be negative before an investment is undertaken? Can the risk premium be negative after the fact? Explain.

note: Please dont give me no Chat GPD answers.

Prever Excel and please show the formula used in excel.

Thanks