I originally posted this in the Game Theroy forum on twoplustwo.com, but no one has replied, dispite it being a popular forum:

I'm analyzing my last 300 seperate sessions of poker. For each session I have the session length and the winnings.

I have calculated the mean win-rate, standard deviation of the mean win-rate and the standard error on the mean win-rate (I hope correctly). The result was -130 $/hr +/- 115 $/h (115 being the standard error)

Therefore in this sample of 300 sessions, my average winrate is some where between -245$/hr and -15$/hr.

My questions

1) With what percent certainty can you say that I am a losing player?

2) With what percent certainty is my winrate between -100 and -160$/hr?

Edit: I changed the numbers from my own for the sake of question 1). I can provide the raw data if that helps.