Question

The mean of the following natural numbers $1,2,3,...,10$ is:

• A. $6.5$
• B. $4.5$
• C. $5.5$
• D. $5.4$

Answer 1

The correct option is C $5.5$

Given, numbers are $1,2,3,..,10$.

Then, number of observations is $n=10$.
We know, sum of $n$ natural numbers numbers $=\frac{n(n+1)}{2}$

When $n=10$, then the sum $=\frac{10(10+1)}{2}$$=\frac{10\times 11}{2}=55$.

We know, Mean is given by,

$\text{Mean}=\frac{\text{Sum of the elements}}{\text{Total number of elements}}$.

$⟹$ Mean $=\frac{55}{10}=\frac{11}{2}=5.5$.

Therefore, option $C$ is correct.