If the mean of $20$ observations is $27.2$,then $\Sigma f_{i} x_{i}$ is ............

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

The marks obtained by $17$ students in a mathematics test (out of $100$) are given below:
$91, 82, 100, 100, 96, 65, 82, 76, 79, 90, 46, 64, 72, 68, 66, 48, 49$
The range of the data is:

If $\bar{x}$ is the mean of $x_{1}, x_{2}, \ldots, x_{n},$ then for $a \neq 0,$ the mean of $a x_{1}, a x_{2}, \ldots, a x_{n}, \frac{x_{1}}{a}, \frac{x_{2}}{a}, \ldots, \frac{x_{n}}{a}$ is

Prepare a continuous grouped frequency distribution from the following data:

Mid-point	Frequency
$5$	$4$
$15$	$8$
$25$	$13$
$35$	$12$
$45$	$6$

Also,find the size of the class intervals.

....... is a branch of Mathematics in which the extraction of meaningful information is studied.