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更新1:
myisland唔該哂你...!
Find Mean and Variance
2011-04-23 8:03 am
As follows:
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回答 (1)
2011-04-23 8:17 am
✔ 最佳答案
E(X) = ∫ x(x/2) dx + ∫ x/3 dx = 1/6 + 5/6 = 1E(X^2) = ∫ (x^2)(x/2) dx + ∫ x^2/3 dx = 1/8 + 19/9 = 161/72
Var(X) = 89/72
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110423000051KK00002