
Normal distribution.
Right, so I've missed quite alot in school and now started revising earlier than I would've. It might not even fall under the 'Advanced' category, sorry if that's the case. Stats don't make sense to me at all so please help.
If the costs of completion of a building are normally distributed with a mean of $700,000 and a standard deviation of $150,000, what are the chances of making a profit if the promised return is $1,000,000 and how much has to be obtained in order to have a 90% chance of making a profit?
Cheers for any tips.

Ok, it seems you should find a zscore here.
$\displaystyle \displaystyle z=\frac{x\mu}{\sigma} =\frac{x700000}{150000}$
Now is the 1000000 also a building cost? if so make it $\displaystyle x$ in the above equation.

Nah, the $1bn is not the building cost, it's supposed to be expected profit which confuses me quite alot (Doh)

I thought so, that isn't to helpful in this situation. Did you post the whole question?
Just for your reference, its actually 1 million dollars not 1 billion.