How Do You Calculate P(X>4Y) with the Given Joint PDF?

  • Thread starter Thread starter Phox
  • Start date Start date
  • Tags Tags
    Joint Pdf
Click For Summary
SUMMARY

The discussion focuses on calculating the probability P(X>4Y) using the joint probability density function f(x,y) = x + 4y, defined for 0 < y < x < 1. Participants confirm the marginal probability density functions p1(x) = 3x² and p2(y) = (-9/2)y² + 4y + (1/2) but debate their relevance to the calculation of P(X>4Y). The consensus suggests that the calculation should directly utilize the joint PDF rather than the marginal PDFs.

PREREQUISITES
  • Understanding of joint probability density functions
  • Knowledge of marginal probability density functions
  • Familiarity with probability calculations involving inequalities
  • Basic calculus for integration
NEXT STEPS
  • Study the derivation of joint probability density functions
  • Learn how to calculate probabilities using joint PDFs
  • Explore the application of inequalities in probability calculations
  • Review integration techniques for calculating probabilities in continuous distributions
USEFUL FOR

Students studying probability theory, statisticians working with joint distributions, and anyone seeking to understand advanced probability calculations.

Phox
Messages
36
Reaction score
0

Homework Statement



Suppose X and Y have the joint probability density function:

f(x,y) = x+4y, 0<y<x<1
f(x,y) = 0 otherwise

Find P(X>4Y)

Homework Equations





The Attempt at a Solution



I'm not sure how to do this. I've already found marginal pdf's for x and y.. although I don't know if they're relevant.

p1(x) = 3x^2
p2(y) = (-9/2)y^2+4y+(1/2)

Thanks for the help
 
Physics news on Phys.org
I agree with your values for the marginals. Although I don't think they are relevant for this question.. There may be a way to do it, making use of the marginals, but that is not the way I did it.

You should start by writing an equation for P(X>4Y) using the equation f(x,y)
 

Similar threads

Replies
11
Views
3K
Replies
5
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
9
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K