Mean Deviation about Mean

Q. The variance of $3,6,9,\dots .,30$ is

1. $72.45$
2. $74.25$
3. $54.36$
4. $48.37$

Q. Mean deviation of the series a, a + d, a + 2d, a + 2nd from its mean is

1. 
2. 
3. 
4. 

Q.

Number of goals scored by Ronaldo in champions league for past 10 years are as follows. {1, 3, 8, 4, 7, 6, 10, 12, 17, 10} Find the mean deviation about the mean.

1. 3.6

2. 3

3. 4

4. 3.4

Q.

If the mean deviation of the numbers $1,1+d,1+2d,\cdot ,1+100d$ from their mean is 255, then $d$ is equal to:

1. 10.1

2. 20.2

3. 20.0

4. 10.0

Q. If the mean deviation of the number $1,1+d,1+2d,....1+100d$ from their mean is $255$ then $d$ is equal to $(d>0)$

1. $10.0$
2. $20.2$
3. $10.1$
4. $20.0$

Q. If the mean deviation about the median of the numbers $a,2a,....,50a$ is $50$. Then $|a|$ equals

1. $4$
2. $5$
3. $2$
4. $3$

Q. The mean of $5$ observations is $5$ and their variance is $12.4$. If three of the observations are $1,2$ and $6$; then the mean deviation from the mean of the data is:

1. $2.8$
2. $2.6$
3. $2.5$
4. $2.4$

Q. If the mean deviation of the data $1,1+d,$ $1+2d,\dots ,1+100d$ from their mean is $255,$ then $d$ is equal to

1. $10.0$
2. $20.0$
3. $10.1$
4. $20.2$

Q. The mean deviation about the mean for the following data :
$5,6,7,8,6,9,13,12,15$ is :

1. $1.5$
2. $3.2$
3. $5$
4. $2.89$

Q. If the mean deviation of the numbers $1,1+d,1+2d,\dots ,1+100d$ from their mean is $255$, then $|d|$ is equal to

1. $20$
2. $10.1$
3. $10$
4. $20.2$