送交者: steven 于 July 16, 2001 02:21:01:
回答: 对不起, 不会英文 由 008temp 于 July 14, 2001 21:52:24:
coin tossing is a pratical experiment, like any other statistical experiment, the sampling space cannot be small. For an ideal coin, the result of tossing a head is 1/2, and it is independent. The reason for that is the event space is small, and events are independent. For a practical coin, after tossing for many times, say 2^10, the result will show that number of head being tossed out and the number of tail are close, probably not equal.
As for 9 heads, what if the next 1000 times contains 525 heads, 475 tails, do you think the 9 head is significant enough?
As I said earlier, when you deal with 9 occurence, you extend the random variable to X=9, which means, you take
all 9 tossing into account, and your event space is not
\ where X \in {H, T}, the space is \, it is a different problem. Also, small probablity
will happen, unless it is 0.