※ 引述《ShellyLiang (星幻恋痕)》之铭言：
: 这是应用统计学的题目:
: It is against the law to discriminate against job applicants
: on the basis of race, religion, sex, or age.
: Of the individuals who apply for a statistcian's position
: in a large corporation, 41% are over 45 years of age.
: The company decides to choose 46 of a very large number of applicants for
: closer screening, claiming that the selection will be random and
: not age-biased.
: Let x be the number in the sample of 46 who are over 45 years of age.
: If you wish to find P(x≦21), the probability that x is at most 21,
: what is the z-score associated with this x-value of 21?
: (Assume that the applicant pool is large enough so that x has a
: binomial probability distribution.)
: 除了解题过程外，
: 我想请问解这题是用到什么观念还是方法?
: 是关于二项分配还是标准常态分配还是其他方法，
: 因为我解了很久都解不出来，
: 希望能给我一些指示，谢谢。
找出平均值跟标准差
0.41*46=18.86
(0.41*0.59*46)^(1/2)=3.367
18.86+z*3.367=21
z=0.636
利用二项式分配可以逼近常态
不保证我一定对 参考用
下面有网站可以看看
http://elderlab.yorku.ca/~aaron/Stats2022/BinomialTest.htm