2017.Fall 12 b ii

tubaguy8tubaguy8
edited October 2021 in Fisher.Visualization

I'm a bit confused by the sample answers for b ii. I think their integral bounds might be incorrect.

Shouldn't the answer be ∫ (from F(M) to F(M+N)) xdF(x)+(M+N)*(1-F(M+N))−M*(1-F(M))?

They post the answer as ∫ (from M to M+N) xdF(x)+(M+N)*(1-F(M+N))−M*(1-F(M)).

Thanks!


Edit - I know the source material uses the latter formula, but I'm not sure why that's correct. I'd think we'd need to integrate from F(M) to F(M+N).

Comments

  • adminadmin

    I believe this is a matter of presentation rather than substance because we're used to thinking about the size of losses and how they change, but we're not as used to thinking in terms of changes in the cumulative distribution. It's rather like writing the integral of x^2 dx from x =2 to x=3 as the integral of x^2 dx from y = 4 to y =9 (and we know/assume x>=0).

    As such, the grader *should* accept both answers.

Sign In or Register to comment.