Roulette Probability Question

[college kid]

I'm just not following where you are getting your numbers from. If you do not hit your number, you will be in solution B, if you do hit it exactly once, you will be in solution C, and if you hit it more than once, you will be in solution A. Where on earth did you get your numbers from??? I can't tell just from looking how likely they seem, but I certainly did not follow you in your post. Anybody else care to put in some actual stats equations???

The answers are of course:

Solution A: the probability of hitting your number two or more times

Solution B: the probability of you not hitting your number

Solution C: the probability of you hitting your number exactly once

I don't know the exact figures, but from reading the posts you all seem to not understand the basics of what is going on. All we need is a normal bell curve and the equations necessarily to calculate the likely hood of the number not hitting, hitting once, and hitting more than once. Period.

[niin]

Uh, isn't that what he computed?

Solution B -- You go broke 36.3% of the time
Solution C -- You end with exactly $36 37.28% of the time
Solution A -- Therefore you end with more than $36 1-.363-.3728=0.2642 or 26.42% of the time


If you hit your number exactly once, you'll have exactly $36. If you hit your number more than once, you'll have more than $36. If you never hit your number, you'll have $0.

elitegimp's post was pretty straightforward.

[pzhon]

[ QUOTE ]
[ QUOTE ]

After 38 spins, which is more likely?

(a) You have more than $36.
(b) You have less than $36 (0 dollars).
(c) You are as likely to have 0 dollars as more than $36.


[/ QUOTE ]
On average, you have $36. When you are below average, you are exactly $36 below average. When you are above average, you are at least $36 above average, perhaps much more. In fact, if you win more than $36, your average win is about $49.46 above average. That means you are about 49.45/36 as likely to lose as to win, since the times you are below average have to balance the times you are above average.

Situation A happens 36.30% of the time.
Situation B happens 26.42% of the time.

[/ QUOTE ]
My arguments above are correct, but I had the labels reversed. You lose 36.20% of the time (b) and win 26.42% of the time (a).

[college kid]

I got confused because he switched the amounts for being up and down and I knew that wasn't it, but I also hadn't actually ran the numbers so I didn't know where he got the percentages from--but now I know those are it. Thanks for explaining!

[gamble4pro]

The "average" you are talking about is practically the probability of hitting that number. The probability is a measure and limit, mathematically speaking. We know that the relative frecquency of occurences converges to that limit (the Law of Large Numbers), but we can predict nothing around it. It is possible to play 1000 times and have no hit as well as having 380 hits. The difference between possible and probable involves a lot of philosophy. Search on the net for the article "The Probability-Based Strategy".