Using the table below, calculate the standard deviation of the portfolio

Demand for Company Products

Probability of this Demand Occurring

Rate of Return if this demand Occurs $($k$)$

Weak

$0\mathrm{.}2$

$-30\%$

Below average

$0\mathrm{.}1$

$-15\%$

Average

$0\mathrm{.}4$

$10\%$

Above Average

$0\mathrm{.}1$

$25\%$

Strong

$0\mathrm{.}2$

$3$Using the table below, calculate the standard deviation of the portfolio

a$.22\mathrm{.}67\%$

b$.18\mathrm{.}85\%$

c$.14\mathrm{.}94\%$