需要知道随机变量X的取值范围,
(一)如果X的取值范围是1,2,3···则由所有情况概率总和为1可知：
r*(p+p^2+p^3+```)=r*p/(1-p)=1,则p=1/(1+r)
（二）如果X的取值范围是0,1,2,3···则由所有情况概率总和为1可知：
r*(1+p+p^2+p^3+```)=r/(1-p)=1,则p=1-r
若为其他情况,同理可解.
猜你喜欢
- 1need special care and attention是什么意思 hold it in my
- 2血红蛋白为什么不是分泌蛋白
- 3just smell the flowers
- 4甲乙丙三个数的和是748,已知甲乙两数的比是5：3,丙数是甲数乙数和的3/8,三个数是多少?
- 5There was nobody at home?（保持句意不变）
- 6"practice makes p____ " means if you keep practicing and don't give up ,you will be very go
- 7请写一两句话,表达自己对某种景物的感受.
- 8polyester 面料与cotton面料比哪个好一些
- 9求以椭圆x²/4+y²/16＝1的焦点为顶点,且与该离心率相同的椭圆的标准方程
- 10In 1963 a panda was born in a zoo for the first time.What zoo was it born in