The difference of the highest and the lowest values in the data is called the ............

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 following table gives the distribution of students of sections $A$ and $B$ of a class according to the marks obtained by them.

Marks	Section $A$ Frequency	Section $B$ Frequency
$0-15$	$3$	$3$
$15-30$	$12$	$16$
$30-45$	$28$	$25$
$45-60$	$30$	$27$
$60-75$	$35$	$40$
$75-90$	$13$	$10$

Represent the marks of the students of both the sections on the same graph by two frequency polygons. What do you observe?

The range of the data: $25, 18, 20, 22, 16, 6, 17, 15, 12, 30, 32, 10, 19, 8, 11, 20$ is

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 $.5$)

State whether each of the following statements is true or false:
$(1)$ The mean of the first four odd natural numbers is $4$.
$(2)$ The highest value of the data is called a range.
$(3)$ The mean of $30$ observations is $30$,then the sum of those observations is $60$.