Re: [問題] 94北科統計
※ 引述《s911125 (江小LO)》之銘言：
: a factory produces 10 glass comtainers daily.itmay be assumed that there is a
: constant probability p=0.1 of producing a defective container.before these
: containers are stored they are inspected and defective ones are set aside.
: suppose that there is a constant probalility r=0.1 that a defective container
: is misclassified.let X equal the number of containers classified as defective
: at the end of a production day.(suppose that all containers which are
: manufactured on a particular day are also inspected on that day.) compute
: P(X=2)?
: a. 0.1937
: b. 0.1714
: c. 0.2541
: d. none of above
: 我的算法 1. 10C2*0.1^2*0.9^8=0.1937
: 2. 10C2*0.01^2*0.99^8=0.00415
: 請問哪個P是正確的 0.1 & 0.01
由機率總和定理:
則經過檢測後的不良率=0.9*0+0.1*0.9=0.09
let X equal the number of containers classified as defective
at the end of a production day
X~B(10, 0.09)
則P(X=2)= C(10,2)* 0.09^2 *0.91^8 =0.1714
=>故選b.
不曉得和你手上的答案是否相同@@
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03/26 00:24, , 1F
03/26 00:24, 1F
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