Finding mean for Grouped Data when class Intervals are not given

Q.

$\sum fx=5x+2$, $\sum f=12$. If the mean of the distribution is 6, what is the value of x?

1. 12

2. 14

3. 18

4. 15

Q. Mean is the used measure of
central tendency.

1. most frequently
2. sometimes
3. rarely

Q.

The mean marks of 100 students were found to be 40. Later on, it was discovered that a score of 53 was misread as 83. Then, the correct mean will be:

1. 37.5

2. 35.6

3. 39.7

4. 38.7

Q. The weights (in kilograms) of ten puppies from the same litter are recorded below:
$1.231.422.011.561.660.921.381.441.521.48$
Calculate: the median weight

Q. If the mean of $x_1$ and $x_2$ is $M_1$ and that of $x_1,x_2,x_3,x_4$ is $M_2$, then the mean of $a{x}_1,a{x}_2,\frac{x_3}{a},\frac{x_4}{a}$
is _____.

1. $\frac{M_1+M_2}{2}$
2. $\frac{a{M}_1+\left(\frac{M_2}{2}\right)}{2}$
3. $\frac{1}{2a}\left[\right(a^2-1)M_1+M_2]$
4. $\frac{1}{2a}\left[2\right(a^2-1)M_1+M_2]$

Q. What is mean?

1. The simple average of the observations
2. The sum of the observations
3. The difference between any two observations
4. The product of the observations

Q. The mean marks of 100 students were found to be 40. Later on, it was discovered that a score of 53 was misread as 83. Then, the correct mean will be:

1. 35.6
2. 39.7
3. 38.7
4. 37.5

Q. The mean of a set of 20 observations is 19.3. The mean is reduced by 0.5 when a new observation is added to the set. The new observation is:

1. 19.8
2. 9.8
3. 9.2
4. 8.8

Q.

If the sum of the deviations of a set of values $x_1,x_2,x_3,\dots ,x_n$ measured from 50 is -10 and the sum of deviations of the values from 46 is 70, then the mean is _____.

1. 49

2. 50

3. 49.5

4. 49.75