here's an entry in the Things That Keep Me Up At Night series.

after tossing a coin nine times, with each toss coming up 'heads' each time, what is the probability that the tenth toss will also come up 'heads'? assume that there are no outside influences or forces acting on the toss (i.e., no air resistence, the coin is perfectly balenced, blah blah blah). it's just you, the coin, and probability.

initially, i thought '50 - 50', an equal chance of a head or a tail, that the first nine tosses had no bearing at all on the tenth. now i'm not sure about that, and i don't know if it's because it really shouldn't be 50 - 50, or if i'm trying to change the laws of the universe.

anyone know a statistician who could ease my mind, or the name of a book that explains why it is or isn't an equal chance (in simple terms. i'm not too bright)?