Statistics

The mean of certain number of observations is 46. If four observation whose main is 52 are removed, the mean becomes 44.5. The original number of observation is:

Choose the most appropriate option. The mean of $72$ items was found to be $63$. If two of the items were misrecorded as $27$ and $9$ instead of $72$ and $90$ respectively, find the correct mean.

There is a set of $80$ observations with a mean of $15$ and a standard deviation of $0$. What is the value of the smallest observation in the set?

The mean of $10$ values of a group is $6$. If among these values, the mean of $4$ values is $7.5$, then the mean of the remaining values will be:

Coefficient of Variation of two distribution are $60 \%$ and $75 \%$ and their S.D are $18$ and $15$ respectively. Find the average of their arithmetic means.

The mean and variance of $7$ observations are $8$ and $16$. If $5$ of these are $2,4,10,12,14$, find the sum of two remaining observations.

The mean of $21$ observations (all different) is $40 .$ If each observations greater than the median are increased by $21 ,$ then mean of observations will become

Six faces of a balanced die are numbered from integers $1$ to $6$. This die is tossed $60$ times and the frequency distribution of the integers obtained is given. Then the mean of the grouped data is Integer $1$ $2$ $3$ $4$ $5$ $6$ Frequency $8$ $9$ $10$ $16$ $9$ $8$

The mean of sequencially arranged 11 observation is 50. The mean of first 6 observations is 49 and the mean of last 6 observations is 52. then the sixth observation is ....

The mean and variances of 10 values of a variables x are 0 and ${ \sigma }^{ 2 }$. If the variable $y={ 5x }^{ 2 }$ then mean of y is:

If $x_1, x_2,......x_{10}$ are $10$ observations, in which mean of $x_1, x_2, x_3, x_4$ is $11$ while mean of $x_5, x_6, ...x_{10}$ is $16$. Also $x_1^2+x^2_2+....x^2_{10}=2000$ then value of standard deviation is?