$9.$ Calculating Returns and Variability You've observed the following returns on Yasmin

Corporation's stock over the past five years: $17$ percent, $9$ percent, $3$ percent, $27$ percent, and

$18$ percent.

a$.$ What was the arithmetic average return on Yasmin's stock over this five$-$year period?

b$.$ What was the variance of Yasmin's returns over this period? The standard deviation?

$10.$ Calculating Real Returns and Risk Premiums In Problem $9,$ suppose the average inflation rate over

this period was $2\mathrm{.}6$ percent and the average T$-$bill rate over the period was $3\mathrm{.}25$ percent.

a$.$ What was the average real return on Yasmin's stock?

b$.$ What was the average nominal risk premium on Yasmin's stock?