SOA #87
Looking at the 6th line in the solution, i.e. E(X20)+ = E(X)  ....
I understand that this line is using the formula E[(X20)+] = E(X)  E[(X^20)],
but how does that second part of the 6th line equate to E[(X^20)]??
And for this particular question, can I use the survival function (derived by finding the distribution function F(x) from the f(x) in the solution and then S(x)= 1  F(x)), and then integrating the survival function from 20 to 80 for the flat f(x) portion + integrating the survival function from 82 to 120 for the declining f(x) portion?
Thank you!
