In any discrete series (when all values are not same) the relationship between $M.D.$ about mean and $S.D.$ is
$M.D. = S.D.$
$M.D.\ge S.D.$
$M.D. < S.D.$
$M.D. \le S.D.$
If $v$ is the variance and $\sigma$ is the standard deviation, then
The mean and standard deviation of $15$ observations are found to be $8$ and $3$ respectively. On rechecking it was found that, in the observations, $20$ was misread as $5$ . Then, the correct variance is equal to......
If the standard deviation of $0, 1, 2, 3, …..,9$ is $K$, then the standard deviation of $10, 11, 12, 13 …..19$ is
Suppose values taken by a variable $x$ are such that $a \le {x_i} \le b$, where ${x_i}$ denotes the value of $x$ in the $i^{th}$ case for $i = 1, 2, ...n.$ Then..