If each observation of the data is increased by $5,$ then their mean

Draw a histogram of the following distribution:

Heights (in $cm$)	Number of students
$150-153$	$7$
$153-156$	$8$
$156-159$	$14$
$159-162$	$10$
$162-165$	$6$
$165-168$	$5$

If the mode of the observations $5, 6, 8, 9, 6, 7, 8, 9, 4, 5, 8, 9, x$ and $10$ is $9$,then $x = $ ............

The following are the marks (out of $100$) of $60$ students in mathematics:
$16, 13, 5, 80, 86, 7, 51, 48, 24, 56, 70, 19, 61, 17, 16, 36, 34, 42, 34, 35, 72, 55, 75, 31, 52, 28, 72, 97, 74, 45, 62, 68, 86, 35, 85, 36, 81, 75, 55, 26, 95, 31, 7, 78, 92, 62, 52, 56, 15, 63, 25, 36, 54, 44, 47, 27, 72, 17, 4, 30$
Construct a grouped frequency distribution table with a class width of $10$,such that one of the classes is $10-20$ ($20$ not included).

Following is the frequency distribution of total marks obtained by the students of different sections of Class $VIII.$

Marks	$100-150$	$150-200$	$200-300$	$300-500$	$500-800$
Number of students	$60$	$100$	$100$	$80$	$180$

Draw a histogram for the distribution above.

Classifying the observations $0, 3, 2, 5, 7, 8, 10, 12, 5, 6, 6, 4, 14, 18, 20$ of a data,the frequency of class $0-5$ is ........