Question

Standard deviation for first $10$ natural numbers is

• A. $5.5$
• B. $3.87$
• C. $2.97$
• D. $2.87$

Answer 1

Answer: (D)

$2.87$

Answer 2

$S.D.$ of first $n$ natural numbers is $\sqrt{\frac{n^{2}-1}{12}}$, Substitute $n = 10$, we get $S.D. =\sqrt{\frac{99}{12}}=\sqrt{8.25}=2.87$