If for a slightly asymmetric distribution,mean and median are $5$ and $6$ respectively,what is its mode?

The mode of the following data set is $0, 1, 6, 7, 2, 3, 7, 6, 6, 2, 6, 0, 5, 6, 0$.

Consider the following frequency distribution:

Class	$0-6$	$6-12$	$12-18$	$18-24$	$24-30$
Frequency	$a$	$b$	$12$	$9$	$5$

If $\text{mean} = \frac{309}{22}$ and $\text{median} = 14$,then the value of $(a-b)^{2}$ is equal to $.....$

For a normal distribution,if the mean is $M$,mode is $M_0$,and median is $M_d$,then:

For a discrete series (where all values are not equal),what is the relationship between Mean Deviation $(M.D.)$,Mean $(Mean)$,and Standard Deviation $(S.D.)$?

In any discrete series (when all values are not same),the relationship between $M.D.$ about mean and $S.D.$ is: