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 .............

Draw a histogram of the following distribution:

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

$A$ class consists of $50$ students out of which $30$ are girls. The mean of marks scored by girls in a test is $73$ (out of $100$) and that of boys is $71$. Determine the mean score of the whole class.

The marks obtained (out of $50$ marks) by $30$ students in a mathematics test are as given below:
$37, 22, 35, 42, 10, 16, 31, 22, 20, 27$
$27, 20, 31, 40, 35, 40, 27, 16, 47, 22$
$40, 22, 35, 20, 37, 20, 37, 47, 42, 31$
Represent this data in a frequency distribution table.

Give five examples of primary data that you can collect from your day-to-day life.