Hi thanks but dint think this answers my question and I'm well aware of actual/observed .... I deal with that stuff everyday at work!
My questions is that I thought the sum of the formula I gave in my original post gives a chi squared distribution. The formula in my original post is not quite the standardised deviance.
Maybe someone can tell me what I'm missing here?
Edit: oh youre saying they're the same- well just squares it. Ok I can see that using the formula you've used. but I thought for the standardised deviance you divide by the standard deviation of the actual number of claims/deaths/whatever
The whole question is a pretty mute point to be honest- it's not difficult ... but just interested to understand why the difference.
Thanks
Last edited by a moderator: Sep 15, 2015