11. Find the standard deviation of 'n' natural numbers

Write the formula to find the standard deviation of first $n$ natural numbers. Using this formula, find the standard deviation of first 11 natural numbers.

 

 

(i) The formula to find the standard deviation of first $n$ natural numbers is $\sqrt{\frac{i^{i}ii}{i}}$

 

(ii) The standard deviation of first 11 natural numbers is .

 

[Note: Enter the answer rounded to two decimal places.]