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]
- A
$316$
- B
$314$
- C
$317$
- D
$315$
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- [JEE MAIN 2021]
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What is the standard deviation of the following series
class
0-10
10-20
20-30
30-40
Freq
1
3
4
2
What is the standard deviation of the following series
|
class |
0-10 |
10-20 |
20-30 |
30-40 |
|
Freq |
1 |
3 |
4 |
2 |