$A$ grouped frequency distribution table with classes of equal sizes using $63-72$ ($72$ included) as one of the class is constructed for the following data:
$30, 32, 45, 54, 74, 78, 108, 112, 66, 76, 88$
$40, 14, 20, 15, 35, 44, 66, 75, 84, 95, 96$
$102, 110, 88, 74, 112, 14, 34, 44$
The number of classes in the distribution will be:

Represent the following data by a bar graph:

Score	Frequency
$1$	$15$
$2$	$13$
$3$	$20$
$4$	$17$
$5$	$20$
$6$	$15$

The mean of the $10$ observations is $68$. If each observation is divided by $2$ and then $6$ is added to each result, find the mean of the new observations so obtained.

Convert the given frequency distribution into a continuous grouped frequency distribution:

Class interval	Frequency
$150-153$	$7$
$154-157$	$7$
$158-161$	$15$
$162-165$	$10$
$166-169$	$5$
$170-173$	$6$

In which intervals would $153.5$ and $157.5$ be included?

Mean of $50$ observations was found to be $80.4$. But later on,it was discovered that $96$ was misread as $69$ at one place. Find the correct mean.

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).