$Z - \bar{x} = \dots \times (M - \bar{x})$

In the usual notations,$Z - M = \ldots \ldots \ldots \quad (M - \bar{x})$

.......... is not a measure of central tendency.

If $\bar{x} = Z - 3$ and $M = 22$,then the mean is ..........

The mean of the following frequency distribution is $28.5$ and the total frequency is $60$. Find the missing frequencies $f_{1}$ and $f_{2}$.

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
Frequency	$6$	$f_1$	$20$	$15$	$f_2$	$4$

Given below is a cumulative frequency distribution showing the marks secured by $50$ students of a class:

Marks	Below $20$	Below $40$	Below $60$	Below $80$	Below $100$
Number of students	$17$	$22$	$29$	$37$	$50$

Form the frequency distribution table for the data.