منتديات الرياضيات العربية - عرض مشاركة واحدة - طلب:مااحتمال انتهاء التجربة بعدد فردي من الرميات

17-04-2009, 08:24 PM

و إليك قاعدة : (برهنها باسكال باستخدام أرقام فيرما )

the probability of exactly n heads in 2n tosses of a fair coin is
given by the product of the odd numbers up to 2n-1 divided by the product
of the even numbers up to 2n.

to get 2 heads in 4 tosses , n =2
1x3 / 2x4 = 3 / 8

Getting Two Heads in Four Tosses of a Coin

each branch has a probability of 1/2,
each outcome is equiprobable (P = 1/16), and the probability of
tossing exactly 2 heads (outcomes marked with *) is 6/16 = 3/8.