The $A.M.$ of a $50$ set of numbers is $38$. If two numbers of the set,namely $55$ and $45$,are discarded,the $A.M.$ of the remaining set of numbers is

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

The number of observations in a group is $40$. If the average of the first $10$ observations is $4.5$ and the average of the remaining $30$ observations is $3.5$,then the average of the whole group is:

$A$ student scores $75\%, 80\%,$ and $85\%$ in three subjects. If the marks of a fourth subject are added,what is the minimum possible average percentage?

Which formula is used to calculate the weighted mean?

Find the median of the numbers $6, 14, 12, 8, 10, 9, 11$.