ผลต่างระหว่างรุ่นของ "Probstat/week5 practice 1"

รุ่นแก้ไขเมื่อ 23:26, 15 กันยายน 2557

1. For a random variable X with variance Var(X). For a constant a, prove that $Var(aX)=a^{2}Var(X)$ .

2. For a non-negative discrete random variable $X$ that takes on values 0,1,2,..., show that $\mathrm {E} [X]=\sum _{i=0}^{\infty }P{X\geq i}$ .

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 == thoretical exercises ==
 . For a random variable ''X'' with variance ''Var(X)''.  For a constant ''a'', prove that <math>Var(aX) = a^2 Var(X)</math>.
+. For a non-negative discrete random variable <math>X</math> that takes on values 0,1,2,..., show that <math>\mathrm{E}[X] = \sum_{i=0}^{\infty} P{ X\geq i }</math>.