Question

Let X(1) < X(2) < X(3) < X(4) < X(5) be the order statistics based on a random sample of size 5 from a continuous distribution with the probability density function
$f(x)=\begin{cases} \frac{1}{x^2}, & 1 < x < \infin\\\ 0, & \text{otherwise.} \end{cases}$
Then the sum of all possible values of r ∈ {1, 2, 3, 4, 5} for which E(X(r)) is finite equals __________

Answer 1

The correct answer is 10.