Banner Ad 1

Collapse

Announcement

Collapse
No announcement yet.

ASM Manual Ex 3.1

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • ASM Manual Ex 3.1

    Am I right in thinking that the reason for bold xy below in

    E(XY) = integral (twice) xy.8/3xy dydx

    is because

    E(X) = integral x.f(x) dx

    E(Y) = integral y.f(y) dy

    ergo the x and y (or xy) would multiply in the same way?

    Miles
    Proper prior planning prevents poor performance!

  • #2
    E(xy)

    Originally posted by mallkins
    Am I right in thinking that the reason for bold xy below in
    E(XY) = integral (twice) xy.8/3xy dydx
    is because
    E(X) = integral x.f(x) dx
    E(Y) = integral y.f(y) dy
    ergo the x and y (or xy) would multiply in the same way?
    Miles
    There is no "because" to it -- E(XY) is the integral of xy multiplied by the density, by definition of the expected value.

    Yours,
    Krzys'
    Want to know how to pass actuarial exams? Go to: smartURL.it/pass

    Comment


    • #3
      And just for clarification, E[XY] isn't always equal to E[X]E[Y]
      Whether you are the lion or the gazelle, when the sun comes up, you better be running.

      Comment

      Working...
      X