Cdf of continous RV transformation

  • Thread starter Thread starter Laura1321412
  • Start date Start date
  • Tags Tags
    Cdf Transformation
Click For Summary
SUMMARY

The cumulative distribution function (CDF) of the random variable Y, defined as Y = 1/X where X has a probability density function (PDF) f(x) = 2x for 0 < x < 1, is computed as P(1/X ≤ y) = P(X ≤ 1/y). The correct CDF is derived as 1 - 1/y² for 1 < y < ∞, contrasting with the initial incorrect calculation of 1/y². This highlights the importance of correctly interpreting transformations of random variables in probability theory.

PREREQUISITES
  • Understanding of probability density functions (PDFs)
  • Knowledge of cumulative distribution functions (CDFs)
  • Familiarity with transformations of random variables
  • Basic calculus for evaluating integrals
NEXT STEPS
  • Study the properties of cumulative distribution functions (CDFs)
  • Learn about transformations of random variables in probability theory
  • Explore integration techniques for evaluating probability distributions
  • Review examples of probability density functions (PDFs) and their corresponding CDFs
USEFUL FOR

Students in statistics or probability courses, educators teaching probability theory, and anyone involved in statistical analysis or data science requiring a solid understanding of random variable transformations.

Laura1321412
Messages
23
Reaction score
0

Homework Statement



Let f(x)= 2x , 0<x<1 , zero elsewhere, be the pdf of X.
Compute the cdf of Y=1/X

Homework Equations



cdf of X = p(X< x)




The Attempt at a Solution



P(1/X <= y)
= P(X <= 1/y)
int 2x from 0 to 1/y
= x^2 eval from 0 to 1/y
= 1/y^2

so the cdf is 1/y^2 for 1<y<infinty

however i don't think this is right... the textbook answers state the cdf as 1-1/y^2


so I am confused. thanks for any help!
 
Physics news on Phys.org
Since 2 < 4, does this imply that 1/2 < 1/4?

RGV
 

Similar threads

Replies
4
Views
2K
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K