Let _ i=1 ^ 9 x_i^2=855. If M is the mean and is the standard deviation of x_1, x_2, , x_9, then what is the value of M^2+ ^2?

NDA 2024 Mathematics question

Let . If is the mean and is the standard deviation of , then what is the value of ?

Answer: (B)

, so .

Question ID VK-030002