For a frequency distribution, standard deviation is computed by
- A$\sigma = \frac{{\sum f(x - \bar x)}}{{\sum f}}$
- B$\sigma = \frac{{\sqrt {\sum f{{(x - \bar x)}^2}} }}{{\sum f}}$
- C$\sigma = \sqrt {\frac{{\sum f{{(x - \bar x)}^2}}}{{\sum f}}} $
- D$\sigma = \sqrt {\frac{{\sum f(x - \bar x)}}{{\sum f}}} $
Similar Questions
The frequency distribution:
$\begin{array}{|l|l|l|l|l|l|l|} \hline X & A & 2 A & 3 A & 4 A & 5 A & 6 A \\ \hline f & 2 & 1 & 1 & 1 & 1 & 1 \\ \hline \end{array}$
where $A$ is a positive integer, has a variance of $160 .$ Determine the value of $A$.
The frequency distribution:
$\begin{array}{|l|l|l|l|l|l|l|} \hline X & A & 2 A & 3 A & 4 A & 5 A & 6 A \\ \hline f & 2 & 1 & 1 & 1 & 1 & 1 \\ \hline \end{array}$
where $A$ is a positive integer, has a variance of $160 .$ Determine the value of $A$.
Let the mean and variance of $12$ observations be $\frac{9}{2}$ and $4$ respectively. Later on, it was observed that two observations were considered as $9$ and $10$ instead of $7$ and $14$ respectively. If the correct variance is $\frac{m}{n}$, where $m$ and $n$ are co-prime, then $m + n$ is equal to
Let the mean and variance of $12$ observations be $\frac{9}{2}$ and $4$ respectively. Later on, it was observed that two observations were considered as $9$ and $10$ instead of $7$ and $14$ respectively. If the correct variance is $\frac{m}{n}$, where $m$ and $n$ are co-prime, then $m + n$ is equal to
- [JEE MAIN 2023]
If the mean and the variance of $6,4, a, 8, b, 12,10, 13$ are $9$ and $9.25$ respectively, then $a+b+a b$ is equal to :
- [JEE MAIN 2025]
The mean and $S.D.$ of the marks of $200$ candidates were found to be $40$ and $15$ respectively. Later, it was discovered that a score of $40$ was wrongly read as $50$. The correct mean and $S.D.$ respectively are...
The mean and $S.D.$ of the marks of $200$ candidates were found to be $40$ and $15$ respectively. Later, it was discovered that a score of $40$ was wrongly read as $50$. The correct mean and $S.D.$ respectively are...
If the standard deviation of the numbers $ 2,3,a $ and $11$ is $3.5$ then which of the following is true ?
If the standard deviation of the numbers $ 2,3,a $ and $11$ is $3.5$ then which of the following is true ?
- [JEE MAIN 2016]