If the modal class of a frequency distribution is $70-85,$ then in the formula for mode,$l=$ ..........

The mean of the following frequency distribution is $60$ and the total frequency is $120$. Find the missing frequencies $f_{1}$ and $f_{2}$.

Class	$10-30$	$30-50$	$50-70$	$70-90$	$90-110$
Frequency	$17$	$f_{1}$	$32$	$f_{2}$	$19$

For a given frequency distribution,$n=100, A=20$ and $\bar{x}=20$. Then,$\Sigma f_{i} d_{i}=\ldots \ldots \ldots . .$

$\Sigma(x_{i} - \bar{x}) = \ldots \ldots \ldots$

The two types of Ogives drawn for a frequency distribution intersect at point $(20, 25)$. Then,the median of the data is .......

In the formula $\bar{x} = A + \frac{\Sigma f_{i} d_{i}}{\Sigma f_{i}}$,$d_{i} =$ .........