If the mean of the observations $x, x+3, x+5, x+7, x+10$ is $9,$ find the mean of the last three observations.

The mean of $10$ observations is $52$. If $12$ is subtracted from each observation,then the mean of the new observations so obtained is:

The weights (in $kg$) of $11$ students are given below:
$37, 42, 40, 39, 41, 35, 37, 36, 40, 40, 42$
Find the median of the data.

The marks obtained (out of $25$ marks) by $40$ students in an examination are as given below:
$\begin{array}{rrrrrrrrrr} 8, & 12, & 23, & 9, & 5, & 20, & 16, & 3, & 6, & 23 \\ 10, & 6, & 21, & 1, & 18, & 17, & 18, & 16, & 16, & 12, \\ 3, & 15, & 21, & 7, & 12, & 5, & 2, & 7, & 13, & 24, \\ 13, & 18, & 8, & 2, & 20, & 5, & 13, & 7, & 23, & 16 \end{array}$
Represent the data given above by a grouped frequency distribution table,taking the class intervals as $0-5, 5-10, \dots$ etc.

The heights (in $cm$) of $12$ students are as follows:
$159, 148, 138, 150, 165, 166, 145, 152, 155, 160, 147, 151$
Find the mean,the median,and the mode.

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.