$($Expected rate of return and risk$)$ Syntex, Inc. is considering an investment in one of two common stocks. Given the information that follows, which investment

is better, based on the risk $($as measured by the standard deviation$)$ and return?

a$.$ Given the information in the table, the expected rate of return for stock A is $15\mathrm{.}6\%.($Round to two decimal places.$)$

The standard deviation of stock A is $\%.($Round to two decimal places.$)$

b$.$ The expected rate of return for stock B is $9\mathrm{.}10\%.($Round to two decimal places.$)$

The standard deviation for stock B is $\%.($Round to two decimal places.$)$

Can you break down how to obtain the standard deviation please?