Tag: arithmetic mean of ap

The average age of 36 student in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years?

The sum of first $n$ natural numbers is given by the expression $(2n^{2}+3n)$. The mean of the given numbers is 

The average weight of 45 students in a class is 25 kg. Five of them whose average weight is 48 kg leave the class and other 5 students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class?

If n A.M.'s are inserted between 3 and 17 such that the ratio of the last mean to the first mean is 3:1, then the value of n is

Four numbers are in proportion. The sum of the square of the four numbers is $50$ and the sum of the means is $5$. The ratio of first two terms is $1 : 3$. What is the average of the four numbers ?

Average of first ten prime numbers is :

A line is such that the algebraic sum of the perpendicular on it from a number of point is zero. The line always passes through a fixed point that is 

Coefficient of variance of a distribution is 60% and the standard deviation is 25. The arithmetic mean of the distribution is

If the arithmetic mean of the numbers $x _{1}, x _{2}, x _{3}.......,x _{3}$ is $\overline{X}$, then the arithmetic mean of numbers $ax _{1}+b, ax _{2}+b, ax _{3}+b,........, ax _{n}+b$, where  $a, b$ are two constants would be 

The average score of a cricketer for 10 matches is 42, find the average for last four matches :