Let Y Bin(4; p) and assume that the conditional distribution of X given that Y = y is
Poi(y). Write down E(X/Y = y). Use the formula E(X) = E(E(X/Y )) to nd E(X).
Have no idea where tostart...
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Let Y Bin(4; p) and assume that the conditional distribution of X given that Y = y is
Poi(y). Write down E(X/Y = y). Use the formula E(X) = E(E(X/Y )) to nd E(X).
Have no idea where tostart...
Start with the formula:Quote:
Originally Posted by sebjory
.
thanks very much for your help.
how ever, i did get to this bit but i found it tough to integrat ethe poisson distribution in this way... i feel im missing something ...
It's a sum, not an integral. Please show the work you've done and where you get stuck.Quote:
Originally Posted by sebjory
of course the poisson distribution is discrete...(Rofl)
however this is exactly where im having trouble- what exactly does this summation mean and how do use it?
You're meant to recognise that when you substitute the conditional pdf intoQuote:
Originally Posted by sebjory
which is 'y' in this case...
therefore E(X) is 4p?
It would appear so.Quote:
Originally Posted by sebjory