# Math Help - survival function

1. ## survival function

Anyone can explain why Expected value is equal to integrate Sy(y) dy?

In my class, I only learned that E(y) = integrate y* fy(y) dy.

Help appreciated!

2. Originally Posted by cm917
Anyone can explain why Expected value is equal to integrate Sy(y) dy?

In my class, I only learned that E(y) = integrate y* fy(y) dy.

Help appreciated!
Read 7.1.3 of WWS509 - Lecture Notes