If $M - \bar{x} = 2$ and $Z = 20.5$,then the median $M = \ldots$ (in $.5$)

Calculate the mean of the following frequency distribution:

Class	$80-90$	$90-100$	$100-110$	$110-120$	$120-130$	$130-140$	$140-150$	$150-160$	$160-170$
Frequency	$6$	$18$	$78$	$80$	$100$	$72$	$0$	$40$	$6$

(in $.55$)

For a given frequency distribution,the total frequency is $25$ and $\Sigma f_{i} x_{i} = 120$. Then,the mean is $\ldots$

The median of the following frequency distribution is $50$ and the total frequency is $60$. Find the missing frequencies $x$ and $y$.

Class	$0-20$	$20-40$	$40-60$	$60-80$	$80-100$
Frequency	$5$	$x$	$20$	$y$	$2$

The frequency distribution table of agricultural holdings in a village is given below:

Area of land (in hectares)	$1-3$	$3-5$	$5-7$	$7-9$	$9-11$	$11-13$
Number of families	$20$	$45$	$80$	$55$	$40$	$12$

Find the modal agricultural holdings of the village (in hectares).

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