Re: [問題] 請問這題該用何方式求解?

作者: rayx (chivalry)   2007-11-08 02:05:39
※ 引述《ShellyLiang (星幻戀痕)》之銘言:
: 這是應用統計學的題目:
: 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.)
: 除了解題過程外,
: 我想請問解這題是用到什麼觀念還是方法?
: 是關於二項分配還是標準常態分配還是其他方法,
: 因為我解了很久都解不出來,
: 希望能給我一些指示,謝謝。
找出平均值跟標準差
0.41*46=18.86
(0.41*0.59*46)^(1/2)=3.367
18.86+z*3.367=21
z=0.636
利用二項式分配可以逼近常態
不保證我一定對 參考用
下面有網站可以看看
http://elderlab.yorku.ca/~aaron/Stats2022/BinomialTest.htm
作者: ShellyLiang (齒令)   2007-11-08 09:54:00
謝謝!!

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