Question

if s.d of 1st n natural numbers is 2,then find the value of n​

Answer 1

Explanation:

The standard deviation of n natural numbers = sqrt [1/12 (n^2 - 1)]

Therefore,

sqrt [1/12 (n^2 - 1)] = 2

on squaring both sides

1/12 ( n^2 - 1) = 4

On multiplying both sides by 12

n^2 - 1 = 48

n2 = 48 + 1 = 49

n = sqrt 49 = 7

The value of n = 7