defence exam Coast Guard Navik GD (General Duty) 02/2025 Mock Test Series Mathematics Statistics Measures of Central Tendency
If the n terms a1 , a2 , ……, an are in A.P. with increment r, then the difference between the mean of their squares & the square of their mean is
1
\(\rm \frac{r^2\{(n-1)^2-1\}}{12}\)
2
\(\rm \frac{r^2}{12}\)
3
\(\rm \frac{r^2{(n^2-1)}}{12}\)
4
\(\rm \frac{n^2-1}{12}\)