Calculate the arithmetic average returns, variances, and standard deviations for datasets X and Y$.$

What's given in the problem

Returns for X:

$15\%$

$15\%$

$,$

$26\%$

$26\%$

$,$

$7\%$

$7\%$

$,$

$-13\%$

$13\%$

$,$

$11\%$

$11\%$

Returns for Y:

$21\%$

$21\%$

$,$

$36\%$

$36\%$

$,$

$13\%$

$13\%$

$,$

$-26\%$

$26\%$

$,$