The marks obtained (out of $100$) by a class of $80$ students are given below:

Marks	Number of students
$10-20$	$6$
$20-30$	$17$
$30-50$	$15$
$50-70$	$16$
$70-100$	$26$

Construct a histogram to represent the data above.

The mean of natural numbers between $1$ to $20$ which are multiples of $3$ is ..........

$A$ die is thrown $1000$ times and the outcomes were recorded as follows:

Outcome	$1$	$2$	$3$	$4$	$5$	$6$
Frequency	$180$	$150$	$160$	$170$	$150$	$190$

If the die is thrown once more,then the probability that it shows $5$ is:

The following table shows a frequency distribution for the speed of cars passing through a particular spot on a highway:

Class interval $(km/h)$	Frequency
$30-40$	$3$
$40-50$	$6$
$50-60$	$25$
$60-70$	$65$
$70-80$	$50$
$80-90$	$28$
$90-100$	$14$

Draw a histogram and a frequency polygon representing the data above.

The marks obtained (out of $100$ marks) by $50$ students in a mathematics test are as given below:
$\begin{array}{lrrrrrrrrr} 10, & 65, & 75, & 37, & 8, & 58, & 35, & 42, & 29, & 52 \\ 19, & 52, & 23, & 61, & 88, & 65, & 18, & 77, & 85, & 49, \\ 12, & 7, & 41, & 75, & 52, & 90, & 30, & 89, & 95, & 62, \\ 16, & 61, & 35, & 68, & 22, & 72, & 56, & 27, & 62, & 93, \\ 25, & 59, & 48, & 81, & 26, & 84, & 60, & 39, & 76, & 50 \end{array}$
Represent the data given above by a grouped frequency distribution table,taking the class intervals as $0-10, 10-20, \dots$ etc.

There are $50$ numbers. Each number is subtracted from $53$ and the mean of the numbers so obtained is found to be $-3.5$. The mean of the given numbers is: (in $.5$)