Question

Let X = {11, 12, 13, ….., 40, 41} and Y = {61, 62, 63, ….., 90, 91} be the two sets of observations. If \(\bar{x}\) and \(\bar{y}\) are their respective means and σ² is the variance of all the observations in X ∪ Y, then \(|\bar{x}+\bar{y}-σ^2|\) is equal to ____.

Answer 1

Correct answer is 603

Since, x_i ∈ X are in A.P. with 31 elements & common difference 1, same is y_i ∈ y, when written in increasing order.