Statistics Test...

Mean of variable series $$\bar{x} = 773$$ and mean deviation 64.4 , then coefficient of mean deviation is 

Algebraic sum of deviation from mean is : 

To  find mean from grouped data on the formula $$ \bar{x} = a + \frac{\sum f_{i}d_{i}}{ \sum f_{i}} d_{i}, $$ is deviation of following from a.

Number of students in a school according to their age are as follows :

The mode of the data$$4, 3, 4, 5, 4, 2, 4, 1$$ will be :

The exam scores of all $$500$$ students were recorded and it was determined that these scores were normally distributed. If Jane's score is $$0.8$$ standard deviation above the mean, then how many, to the nearest unit, students scored above Jane?(Area under the curve  below $$z=0.8 \ is \ 0.7881$$)

Find the variance of the series 5, 8, 11, 14 and 17.....

The sum of the squares of deviations of 10 items about mean 50 is 250 .The coefficient of variation is 

The probability distribution of a random variable $$X$$ is given below:

The greatest value of a collection of data is $$72$$ and the least value is $$28$$. Then the coefficient of range is.