作者s911125 (江小LO)
看板Grad-ProbAsk
标题[问题] 统计问题
时间Mon Mar 23 17:01:28 2009
the repair time (in hours) for a certain electronically controlled milling
machine follow the density function
f(X)=4xe^(-2x) x>0
X的动差母函数为何?
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1F：→ haolihy:照定义做 M(t)=E(e^(tx)) 03/23 17:05