Here is the scenario:
The roulette game consists of a small ball and a wheel with 38 numbered pockets around the edge. As the wheel is spun, the ball bounces around randomly until it settles down in one of the pockets. Suppose random variable X represents the (monetary) outcome of a $1 bet on a single number ("straight up" bet). If the bet wins (which happens with probability 1/38 in American roulette), the payoff is $35; otherwise the player loses the bet.
Expected value for the above bet could be calculated as :
-1 * 37/38 + 35 * 1/38
which comes equal to -0.0526. Now what does it really mean? Can expected value change as the total number of bets increases? If yes, what does the above number actually mean? If it will not change with the increasing number of bets, are there some other factors that could influence the expected value?