wuzx · 2021年07月29日
NO.PZ2019040801000019
问题如下：
A survey shows that 30% of the offices have printers in this building. Assuming a binomial probability distribution, what is the probability that exactly three businesses will have a printer in a random selection of five businesses?
选项：
A. 0.0338.
B. 0.0576.
C. 0.1323.
D. 0.1424.
解释：
C is correct.
考点：二项分布
解析：5个办公室里3个有打印机的概率是:
[5! / 3!(5-3)!]*(0.3)3*(0.7)5-3 = 10*(0.027)*(0.49) = 0.1323
为什么要乘以0.7的2次方NO.PZ2019040801000019问题如下A survey shows th30% of the offices have printers in this builng. Assuming a binomiprobability stribution, whis the probability thexactly three businesses will have a printer in a ranm selection of five businesses?A.0.0338.B.0.0576.C.0.1323.0.1424.C is correct.考点二项分布解析5个办公室里3个有打印机的概率是:[5! / 3!(5-3)!]*(0.3)3*(0.7)5-3 = 10*(0.027)*(0.49) = 0.1323怎么知道是C（3，5）不是C（5，3）
NO.PZ2019040801000019问题如下 A survey shows th30% of the offices have printers in this builng. Assuming a binomiprobability stribution, whis the probability thexactly three businesses will have a printer in a ranm selection of five businesses?A.0.0338.B.0.0576.C.0.1323.0.1424.C is correct.考点二项分布解析5个办公室里3个有打印机的概率是:[5! / 3!(5-3)!]*(0.3)3*(0.7)5-3 = 10*(0.027)*(0.49) = 0.1323二项分布没找到这个公式
题目有误，提干不全
