Read gambling problem/Standard deviation Posted: May 23, 2007 4:57 AM Click to edit this message... Click to see the message monospaced in plain text Plain Text Click to reply to this topic Reply I'm analyzing some data from online gambling sites.I'm trying to prove they are stealing the customers. I'm not an expert in math ....just having "common sense" knowledge. Here is the problem I need to solve: I have a series of N independent event where I have a chance ( W ) to win some money ( P ) At the end of day my mathematical expectation is : E= sum after i (W*P) In reality I will have won R dollars after these N independe events. If N is big then R and E should converge somehow. Is it possible to apply here some Standard deviation/Chebyshev's inequality/Weighted standard deviation to get some statistical interpretation about this? I would really like a formula that will say to me something like this: There is a 80% chance that the possible values of R to be in (E-x,E+x) range.