For a given frequency distribution,$A=325, c=50, \Sigma f_{i} u_{i}=28$ and $\Sigma f_{i}=200$. Then,mean $\bar{x}=\ldots \ldots \ldots . .$

If $x_{i}$ are the midpoints of the class intervals of grouped data,$f_{i}$ are the corresponding frequencies,and $\bar{x}$ is the mean,then $\sum (f_{i} x_{i} - f_{i} \bar{x})$ is equal to

The following table shows the cumulative frequency distribution of marks of $800$ students in an examination:

Marks	Number of students
Below $10$	$10$
Below $20$	$50$
Below $30$	$130$
Below $40$	$270$
Below $50$	$440$
Below $60$	$570$
Below $70$	$670$
Below $80$	$740$
Below $90$	$780$
Below $100$	$800$

Construct a frequency distribution table for the data above.

For the following data,the median class is $\ldots \ldots \ldots$

Class	$0-10$	$10-20$	$20-30$	$30-40$	$40-50$
Frequency	$12$	$18$	$20$	$17$	$13$

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

For a given frequency distribution,assumed mean $A = 25$,$\Sigma f_{i} d_{i} = 120$ and $\Sigma f_{i} = 140$. Then,the mean $\bar{x} = \dots$