The probability that a patient recovers from a delicate heart operation is 0.9. Of the next 100 patients having this operation, what is the probability that
(a) between 84 and 95 inclusive survive?
(b) fewer than 86 survive?
probability?
2015-11-23 3:56 pm
回答 (1)
2015-11-23 9:17 pm
u = np = 100*0.9 = 90
σ² = np(1-p) = 100*0.9*0.1 = 9
σ = 3
(a) p(x<95) - p(x<84)
= p[z < (95-90)/3] - p[z < (84-90)/3]
= p(z<1.67) - p(z<-2)
= 0.95221 - 0.02275
= 0.92946
(b) p(x<86)
= p[z < (86-90)/3]
= p(z<-1.33)
= 0.091211
σ² = np(1-p) = 100*0.9*0.1 = 9
σ = 3
(a) p(x<95) - p(x<84)
= p[z < (95-90)/3] - p[z < (84-90)/3]
= p(z<1.67) - p(z<-2)
= 0.95221 - 0.02275
= 0.92946
(b) p(x<86)
= p[z < (86-90)/3]
= p(z<-1.33)
= 0.091211
收錄日期: 2021-04-25 14:52:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20151123075617AAA0Dkg