If $Z - M = 4$,then $M - \bar{x} = \dots$

In a frequency distribution,the modal class is $70-85$ with frequency $25$. The frequencies of the classes succeeding and preceding the modal class are $20$ and $8$ respectively. Then,the values of $f_{0}, f_{1}$ and $f_{2}$ are respectively.

The median of the following frequency distribution is $28.5$ and the total frequency is $60$. Find the missing frequencies $x$ and $y$.

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
Frequency	$5$	$x$	$20$	$15$	$y$	$5$

Construct the cumulative frequency distribution of the following distribution:

Class	$12.5-17.5$	$17.5-22.5$	$22.5-27.5$	$27.5-32.5$	$32.5-37.5$
Frequency	$2$	$22$	$19$	$14$	$13$

Will the median class and modal class of grouped data always be different? Justify your answer.

Daily wages of $110$ workers,obtained in a survey,are tabulated below:

Daily wages (in $Rs.$)	Number of workers
$100-120$	$10$
$120-140$	$15$
$140-160$	$20$
$160-180$	$22$
$180-200$	$18$
$200-220$	$12$
$220-240$	$13$

Compute the mean daily wages of these workers (in $Rs.$).