For a given frequency distribution,$\Sigma f_{i} x_{i} = 1790$ and $\Sigma f_{i} = 50$. Then,the mean $\bar{x} = $ ..........

For a given frequency distribution,$n=100$ and $\Sigma f_{i} x_{i}=245$. Then,$\bar{x}=\ldots \ldots \ldots \ldots$

In the formula $\bar{x} = A + \frac{\Sigma f_{i} u_{i}}{\Sigma f_{i}} \times c$,$c$ represents .......

The following distribution gives the daily income of $50$ workers of a factory.

Daily income (in Rs.)	$100-120$	$120-140$	$140-160$	$160-180$	$180-200$
Number of workers	$12$	$14$	$8$	$6$	$10$

Convert the distribution above to a less than type cumulative frequency distribution,and draw its ogive.

The mean of $5$ observations is $16$. If an observation $5$ is replaced by $-5$,the new mean is ...........

The mean of the following frequency distribution is $18$. Find the missing frequency $f$.

Class	$11-13$	$13-15$	$15-17$	$17-19$	$19-21$	$21-23$	$23-25$
Frequency	$3$	$6$	$9$	$13$	$f$	$5$	$4$