How to find E(1/X)?

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Can someone please explain to me how to do question 7d? Thanks heaps!

1 Answer
sjc
Jan 13, 2018

#0.12(2dp)#

Explanation:

#for discrete pdf

#E(f(x))=sum_(all" " x)f(x)P(X=x)#

so

#E(1/x)=sum_(all" "x)(1/x)P(X=x)#

putting this into a table for ease of calculation

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#E(1/X)=0.005+0.838383..+0.01+0.006+0.0066#

#E(1/X)=0.1150..=0.12 (2dp)#

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