Y is the present-value random variable of an annuity that pays 1 at the beginning of each year that (x) survives.

You are given:

(i) E(Y) @ delta = 10

(ii) E(Y) @ 2delta = 6.

(iii) i = 1/24

Calculate the variance of Y.

The equation for the Var(Y) to use is 1/d2 * [(^2)A_x – A_x^2]

(Excuse the notation the 2's are raised and the x's are subscripts)

I got 1/d^2 to be 625 and I thought (i) was saying that A_x = 10 and (ii) that (^2)A_x = 6, but plugging these values in doesn’t return the right answer. Does anyone know what I’m doing wrong? Thanks!