当彩票分两阶段进行,每次中奖的概率只有50%时,最后中奖的概率是()。
A.50%
B.45%
C.25%
D.2%
A.50%
B.45%
C.25%
D.2%
第2题
第3题
设贝努里试验进行到第r次成功出现为止(每次试验中成功的概率为p,q=1-p),令X为试验进行的次数,则事件X=k等价于“第k次试验出现成功,并且在其前k-1次试验中成功r-1次",因此
此分布称为负二项分布,当r=1时,化为几何分布,
第4题
A.行政管理价值
B.历史价值
C.第一价值
D.第二价值
第5题
(1)试求各等奖的中奖概率pi(i=1,2,…,7);
(2)试求中奖的概率。
第6题
从(0,1)中陆机地取两个数,求:
(1)两个数之和小于6/5的概率:
(2)两个数之积小于1/4的概率。
第8题
理查德正在决定要不要购买州发行的彩票,每张彩票的价格为1美元,取得回报的概率如下所示:
(1)如果理查德购买了一张彩票,它的期望收益是多少?方差呢?
(2)理查德的绰号是“无风险的草堆”,因为他对风险极度地规避。他会购买彩票吗?
(3)理查德获得了1000张彩票。讨论一下你将怎样确定他愿意卖出这1000张彩票的最低价格?
(4)从长期来看,给定彩票的价格和回报/概率表,你认为该州可以从该活动中得到什么?
Richard is deciding whether to buy a state lottery ticket. Each ticket costs $ 1, and the probability of winning payoff is given as follows:
a. What is the expected value of Richard' s payoff if he buys a lottery ticket? What is
the variance?
b. Richard' 8 nickname is“No-risk Rick". He is an extremely risk-averse individual. Would he buy the ticket?
e. Richard has been given 1000 lottery tickets. Discuss how you would determine the smallest amount for which he would be willing to sell all 1000 tickets.
d. In the long run, given the price of the lottery tickets and the probability/return table, what do you think the state would do about the lottery?
第10题
临床因抽样因素使二药出现差别,而实际AB两药物无明显差别,通常不允许这种情况出现的概率为
A.1%.
B.<1%.
C.≤1%.
D.5%.
E.≤5%.
第11题
A.要反复堆掺三次之后在压平
B.每次铲起的煤样,不宜过多
C.每次铲起的煤样,要分两三次洒落在新锥顶端
D.要交互从煤样堆两边对角贴底逐锹铲起