Question

The standard deviation of first 10 natural numbers is

(a) 5.5 (b) 3.87 (c) 2.97 (d) 2.87

Answer 1

We know that the standard deviation of first n natural number is $\sqrt{\frac{n^2-1}{12}}$.

∴ Standard deviation of first 10 natural numbers

$$\begin{gathered} =\sqrt{\frac{{10}^2-1}{12}} \\ =\sqrt{\frac{99}{12}} \\ =\sqrt{8.25} \\ =2.87 \end{gathered}$$

Hence, the correct answer is option (d).