NO.PZ2019040801000073
问题如下:
Robin Hill is taking a difficult multiple choice exam. There are 5 questions in the exam and each question has four choices. The choices are almost the same in each question. which of the following amouts is closest to the probability that he will get more than 3 questions correct by randomly guessing ?
选项:
A.3.0%.
B.8.79%.
C.1.56%.
D.25.0%.
解释:
C is correct.
考点:二项分布概率计算
解析:二项分布中答对一题概率是25%,5道题,
正确4道,5道的可能性分别是:
P(4) = 5 x (0.25)4 x (0.75)1= 0.0146484
P(5) = 1x (0.25)5x (0.75)0 = 0.0009766
0.01464 + 0.00098 = 1.562%
老师,是否可以列举,less than、fewer than, more than。哪个是大于等于,小于等于,小于、大于,这几个表示?