The variance of the data $1, 2, 3, 5, 8, 13, 17$ is approximately

If the variance of the first $n$ natural numbers is $10$ and the variance of the first $m$ even natural numbers is $16$,then $m + n$ is equal to

Two teams $A$ and $B$ have the same mean and their coefficients of variation are $4$ and $2$,respectively. If $\sigma_A$ and $\sigma_B$ are the standard deviations of teams $A$ and $B$ respectively,then the relation between them is

Find the standard deviation for the following data:

${x_i}$	$3$	$8$	$13$	$18$	$23$
${f_i}$	$7$	$10$	$15$	$10$	$6$

The variance of the observations $8, 12, 13, 15, 22$ is:

If $A$ and $B$ are the variances of the first $n$ even numbers and the first $n$ odd numbers respectively,then: