is known that $20$ percent of new hiring employees change their jobs in the first year. Assuming that this claim is true, and Let $x$ represents the number of employees who change his jobs in the first year. A random sample of $15$ is selected $.$ use Table of Binomial in "Statistical Tables" to solve the following questions Find the standard deviations of $x$

$1\mathrm{.}55$

$2\mathrm{.}4$

$1\mathrm{.}55-$

$9$

The probability that more than $8$ persons change their job in the first $*$ year

$0\mathrm{.}3057$

$0\mathrm{.}5187$

$001.$