Statistics, Statistical Analysis, Normal Distribution, Central Limit Theorem, Cdf.
six-sided die and you want to play a game with your friend. The rules are simple: you roll the die and if you get a 6, you win 10 rupees. If you get any other number, you lose 1 rupee. You can play as many times as you want, but you have to stop when you run out of money or when you decide to quit.