If the standard deviation of $0, 1, 2, 3, …..,9$ is $K$, then the standard deviation of $10, 11, 12, 13 …..19$ is
$K$
$K + 10$
$K + \sqrt {10} $
$10\ K$
The sum of squares of deviations for $10$ observations taken from mean $50$ is $250$. The co-efficient of variation is.....$\%$
A data consists of $n$ observations
${x_1},{x_2},......,{x_n}.$ If $\sum\limits_{i - 1}^n {{{({x_i} + 1)}^2}} = 9n$ and $\sum\limits_{i - 1}^n {{{({x_i} - 1)}^2}} = 5n,$ then the standard deviation of this data is
Let the mean of the data
$X$ | $1$ | $3$ | $5$ | $7$ | $9$ |
$(f)$ | $4$ | $24$ | $28$ | $\alpha$ | $8$ |
be $5.$ If $m$ and $\sigma^2$ are respectively the mean deviation about the mean and the variance of the data, then $\frac{3 \alpha}{m+\sigma^2}$ is equal to $..........$.
Determine mean and standard deviation of first n terms of an $A.P.$ whose first term is a and common difference is d.
If each of given $n$ observations is multiplied by a certain positive number $'k'$, then for new set of observations -