Question

# Find the mean of the first five numbers which belong to the set of natural numbers.

Hint:- Let us first find sum of numbers and then divide that by 5 because Mean = $\dfrac{{{\text{Sum of all Observations}}}}{{{\text{Total number of observations}}}}$.

As we know that we had to find the mean of the first five natural numbers.
Natural numbers are those numbers which belong to the set having first number one and goes till infinity.
So, the set of natural numbers will be { 1, 2, 3, 4, 5, 6, …………. }.
So, now from the set of natural numbers.
First five numbers will be 1, 2, 3, 4 and 5.
So, the sum of these five numbers is 1 + 2 + 3 + 4 + 5 = 15.
Total numbers of numbers will be 5.
So, now as we know that the mean of n numbers is given as $\dfrac{{{\text{Sum of n Numbers}}}}{{\text{n}}}$.
So, mean of first five natural numbers will be,
Mean = $\dfrac{{{\text{Sum of first five natural numbers}}}}{5}$ = $\dfrac{{{\text{15}}}}{{\text{5}}}$ = 3
Hence, the mean of the first five natural numbers will be equal to 3.
Note:- Whenever we come up with this type of problem then first, we have to write a set of required numbers and then add these numbers to get their sum. After that divide sum of these numbers by the total number of numbers to get the required mean of these numbers. This will be the easiest and efficient way to find the solution of the problem.