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...
- A
$14.98, 39.95$
- B
$39.95, 14.98$
- C
$39.95, 224.5$
- D
None of these
Similar Questions
Find the mean and variance for the data
${x_i}$
$6$
$10$
$14$
$18$
$24$
$28$
$30$
${f_i}$
$2$
$4$
$7$
$12$
$8$
$4$
$3$
Find the mean and variance for the data
| ${x_i}$ | $6$ | $10$ | $14$ | $18$ | $24$ | $28$ | $30$ |
| ${f_i}$ | $2$ | $4$ | $7$ | $12$ | $8$ | $4$ | $3$ |
The mean of the numbers $a, b, 8, 5, 10$ is $6$ and the variance is $6.80.$ Then which one of the following gives possible values of $a$ and $b$ $?$
The mean of the numbers $a, b, 8, 5, 10$ is $6$ and the variance is $6.80.$ Then which one of the following gives possible values of $a$ and $b$ $?$
- [AIEEE 2008]
The diameters of circles (in mm) drawn in a design are given below:
Diameters
$33-36$
$37-40$
$41-44$
$45-48$
$49-52$
No. of circles
$15$
$17$
$21$
$22$
$25$
Calculate the standard deviation and mean diameter of the circles.
[ Hint : First make the data continuous by making the classes as $32.5-36.5,36.5-40.5,$ $40.5-44.5,44.5-48.5,48.5-52.5 $ and then proceed.]
The diameters of circles (in mm) drawn in a design are given below:
| Diameters | $33-36$ | $37-40$ | $41-44$ | $45-48$ | $49-52$ |
| No. of circles | $15$ | $17$ | $21$ | $22$ | $25$ |
Calculate the standard deviation and mean diameter of the circles.
[ Hint : First make the data continuous by making the classes as $32.5-36.5,36.5-40.5,$ $40.5-44.5,44.5-48.5,48.5-52.5 $ and then proceed.]
Mean and standard deviation of 100 observations were found to be 40 and 10 , respectively. If at the time of calculation two observations were wrongly taken as 30 and 70 in place of 3 and 27 respectively, find the correct standard deviation.
Mean and standard deviation of 100 observations were found to be 40 and 10 , respectively. If at the time of calculation two observations were wrongly taken as 30 and 70 in place of 3 and 27 respectively, find the correct standard deviation.
The variance of first $50$ even natural numbers is
The variance of first $50$ even natural numbers is