If the mean deviation about the mean of the numbers $1,2,3, \ldots ., n$, where $n$ is odd, is $\frac{5(n+1)}{n}$, then $n$ is equal to
If the mean deviation about the mean of the numbers $1,2,3, \ldots ., n$, where $n$ is odd, is $\frac{5(n+1)}{n}$, then $n$ is equal to
- [JEE MAIN 2022]
- A
$20$
- B
$25$
- C
$23$
- D
$21$
Similar Questions
Mean of $5$ observations is $7.$ If four of these observations are $6, 7, 8, 10$ and one is missing then the variance of all the five observations is
Mean of $5$ observations is $7.$ If four of these observations are $6, 7, 8, 10$ and one is missing then the variance of all the five observations is
- [JEE MAIN 2013]
In any discrete series (when all values are not same) the relationship between $M.D.$ about mean and $S.D.$ is
In any discrete series (when all values are not same) the relationship between $M.D.$ about mean and $S.D.$ is
The variance of first $50$ even natural numbers is
The variance of first $50$ even natural numbers is
If both the means and the standard deviation of $50$ observations $x_1, x_2, ………, x_{50}$ are equal to $16$ , then the mean of $(x_1 - 4)^2, (x_2 - 4)^2, …., (x_{50} - 4)^2$ is
If both the means and the standard deviation of $50$ observations $x_1, x_2, ………, x_{50}$ are equal to $16$ , then the mean of $(x_1 - 4)^2, (x_2 - 4)^2, …., (x_{50} - 4)^2$ is
- [JEE MAIN 2019]
The data is obtained in tabular form as follows.
${x_i}$
$60$
$61$
$62$
$63$
$64$
$65$
$66$
$67$
$68$
${f_i}$
$2$
$1$
$12$
$29$
$25$
$12$
$10$
$4$
$5$
The data is obtained in tabular form as follows.
| ${x_i}$ | $60$ | $61$ | $62$ | $63$ | $64$ | $65$ | $66$ | $67$ | $68$ |
| ${f_i}$ | $2$ | $1$ | $12$ | $29$ | $25$ | $12$ | $10$ | $4$ | $5$ |