The arithmetic mean of the following discrete data $12, 14, 20, 23, 25, 32$ is given by

Find the mean of the following frequency distribution:

$x_i$	$5$	$15$	$25$	$35$	$45$	$55$
$f_i$	$12$	$18$	$27$	$20$	$17$	$6$

The arithmetic mean of the first $n$ natural numbers is:

Which one of the following measures of central tendency is the most suitable for evaluating the intelligence of students based on their marks?

$A$ student obtains $75\%$,$80\%$,and $85\%$ in three subjects. If the marks of a fourth subject are added,then his average cannot be less than.....$\%$

The median of a set of $9$ distinct observations is $20.5$. If the four largest observations of the set are increased by $2$,what will be the median of the new set?