Statistics Help @ Talk Stats Forum - Probability

Chance of Beating the House In Roulette

kxiao — Sun, 19 May 2013 19:27:10 GMT

Hi, I was wondering how I could calculate this.
I tried two different methods and got the same answer, but I'm not sure if I'm attacking the problem correctly.
I'm trying to find the probability of beating the house by the time you get to spin #x

The methods I tried were

Pcurrent = (1-Pprevious)*Pwin + Pprevious
Pprevious = chance that you won last time
Pwin = chance of landing on the color you chose

Pcurrent = Pprevious + Pwin * (1-Pwin)^(x-1)
Pprevious = chance that you won last time
Pwin = chance of landing on the color you chose
x = spin number

Edit: I guess the main problem is that I don't know what question I should be asking:
What's the chance of winning at least once by the time you get to spin x? <-- Probably?
What's the chance of winning on the last turn by the time you get to spin x?

Binomial variability

Nadahmed — Sun, 19 May 2013 19:25:20 GMT

Hi,
I have in my research 45 children who took a test twice and the score is either (correct or incorrect).
I calculated confidence intervals for the difference between the scores in the first and second session.

How do I find out if the score is within the binomial variability or not?

Thank you?

correct probability distribution

worldofquery — Sun, 19 May 2013 07:42:43 GMT

stupid question i know, but when a question asks me to identify the correct method of PB what exactly do i have to do? thanks :)