What is the population variance and standard deviation?

Class A

Time

Class B

Time

$1$

$39$

$1$

$48$

$2$

$42$

$2$

$36$

$3$

$49$

$3$

$40$

$4$

$56$

$4$

$41$

$5$

$69$

$5$

$45$

$6$

$61$

$6$

$37$

$7$

$37$

$7$

$39$

$8$

$31$

$8$

$30$

$9$

$45$

$9$

$49$

$10$

$53$

$10$

$36$

$$

a$.$

$83\mathrm{.}35$; $9\mathrm{.}12$

b$.$

$93\mathrm{.}82$; $9\mathrm{.}68$

c$.$

$87\mathrm{.}35$; $9\mathrm{.}34$

d$.$

$78\mathrm{.}82$; $8\mathrm{.}87$