Calculate the mean of the scores of $20$ students in a mathematics test:

Marks	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$
Number of students	$2$	$4$	$7$	$6$	$1$

For some given data,if $Z - M = 2$ and $\bar{x} = 33.5$,then $Z = \ldots \ldots \ldots$ (in $.5$)

In the formula $M = l + \frac{(\frac{n}{2} - cf)}{f} \times c$ for the median,$cf = \ldots \ldots \ldots$

In the formula $M = l + \frac{(\frac{n}{2} - cf)}{f} \times h$ for the median,$n = \ldots \ldots \ldots$

The following are the ages of $300$ patients getting medical treatment in a hospital on a particular day:

Age (in years)	$10-20$	$20-30$	$30-40$	$40-50$	$50-60$	$60-70$
Number of patients	$60$	$42$	$55$	$70$	$53$	$20$

Form:
$(i)$ Less than type cumulative frequency distribution.
$(ii)$ More than type cumulative frequency distribution.

In the formula $Z = l + \left( \frac{f_{1} - f_{0}}{2f_{1} - f_{0} - f_{2}} \right) \times c$ for the mode,$l = \ldots \ldots \ldots$