Question 1029370
{{{f(x)=dF/dx=18/x^3}}} for {{{x>3}}}
{{{f(x)=0}}} for {{{x<=3}}}
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So then,
{{{p(x<=5)=int((18/x^3),dx,3,5)=F(5)-F(3)=1-9/25-0=16/25}}}
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{{{p(x<=8)=F(8)-F(3)=1-9/64-0=55/64}}}
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{{{E=int((x*f(x)),dx,3,infinity)}}}
{{{E=int((18/x^2),dx,3,infinity)}}}
{{{E=-18/x+C}}}
{{{E=0-(-18/3)}}}
{{{E=6}}}