The mean of five numbers is $30$. If one number is excluded,their mean becomes $28$. The excluded number is:

If the marks obtained by the $20$ students are $6, 4, 9, 5, 9, 3, 7, 7, 5, 6, 9, 4, 10, 10, 4, 3, 6, 7, 9, 9$,then the mode of this data is .............

Ten observations $6, 14, 15, 17, x+1, 2x-13, 30, 32, 34, 43$ are written in an ascending order. The median of the data is $24$. Find the value of $x$.

Below is the distribution of "more than" type of marks obtained by $50$ students in a $100$ marks examination. Prepare the grouped frequency distribution from that.

Obtained marks	No. of Students
$0$ or more than $0$	$50$
$20$ or more than $20$	$48$
$40$ or more than $40$	$40$
$60$ or more than $60$	$31$
$80$ or more than $80$	$10$

Represent the following data by a bar graph:

Name of student	Kavya	Ariv	Ahaan	Arya	Arushi
Marks scored	$90$	$80$	$50$	$60$	$40$

If the mean of $20$ observations is $27.2$,then $\Sigma f_{i} x_{i}$ is ............