由F算出機率密度f
f(x)=3/8, x=-3
f(x)=1/8, x=0
f(x)=1/4, x=3
f(x)=1/4, x=4
E(x)=3/8*(-3)+1/8*0+1/4*3+1/4*4=5/8
E(x^2-2|x|)=3/8*(9-6)+1/8*(0-0)+1/4*(9-6)+1/4*(16-8)=31/8
E(x*|x|)=3/8*(-9)+1/8*0+1/4*9+1/4*16=23/8
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由 p 於 星期五 十一月 03, 2006 11:33 pm
[數學] Distribution function 請問有人有可以幫我寫下這些步驟 (有答案)
由 yu-ju 於 星期二 十月 17, 2006 7:37 am
#ed_op#DIV#ed_cl#The distribution function of a random cariable X is given by#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#F(X)= 0 if X< -3#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# 3/8 if -3≤X<0#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# 1/2 if 0≤X<3#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# 3/4 if 3≤X<4#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# 1 if X≥4#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#Calculate E(X), E( X#ed_op#SUP#ed_cl#2 #ed_op#/SUP#ed_cl#-2│X│) and E( X│X│) ?#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#The solution are E(X) =5/8 E( X#ed_op#SUP#ed_cl#2 #ed_op#/SUP#ed_cl#-2│X│) =31/8 E( X│X│)=23/8#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#請問一下這些步驟要怎麼做? 我算來算去答案都不符合正確答案呢 >.<#ed_op#/DIV#ed_cl#