Probability Distribution of R.V r: E_m[m exp(-rm)]

Click For Summary
SUMMARY

The probability distribution of the random variable (R.V) r is initially defined as f(r) = m exp(-rm), where m is a deterministic value. However, when m is treated as a random variable with its own distribution g(m), the correct approach to find the probability distribution of r is to compute f(r) = E_m[m exp(-rm)], integrating over the distribution of m. The final distribution f(r) should not depend on m after this integration, confirming the necessity of weighting f(r) by g(m) and integrating it over the range of m.

PREREQUISITES
  • Understanding of probability distributions and random variables
  • Familiarity with the concept of statistical expectation E_m
  • Knowledge of integration techniques in probability theory
  • Basic understanding of deterministic versus stochastic variables
NEXT STEPS
  • Study the concept of expectation in probability theory, focusing on E_m.
  • Learn about integrating probability distributions, particularly in the context of random variables.
  • Research mathematical references on probability distributions, such as "Probability and Statistics" by Morris H. DeGroot.
  • Explore the implications of weighting functions in probability distributions and their applications.
USEFUL FOR

Students and researchers in statistics, mathematicians working with probability theory, and anyone involved in modeling random variables and their distributions.

gkannan16
Messages
9
Reaction score
0

Homework Statement



Assuming 'm' is deterministic the probability distribution of a Random Variable(R.V) r is f(r)=m exp(-rm) Now m itself is a another R.V with a probability distribution g(m). Is it correct to say that now the probability distribution of 'r' is f(r)=E_m [m exp(-rm)] where E_m is the statistical expectation operation with respect to 'm'. If it is correct can some one give me a mathematical reference (some journal publications or book)?


Homework Equations



f(r)=m exp(-rm)

The Attempt at a Solution



 
Physics news on Phys.org
gkannan16 said:

Homework Statement



Assuming 'm' is deterministic the probability distribution of a Random Variable(R.V) r is f(r)=m exp(-rm) Now m itself is a another R.V with a probability distribution g(m). Is it correct to say that now the probability distribution of 'r' is f(r)=E_m [m exp(-rm)] where E_m is the statistical expectation operation with respect to 'm'. If it is correct can some one give me a mathematical reference (some journal publications or book)?


Homework Equations



f(r)=m exp(-rm)

The Attempt at a Solution


That doesn't look right. The final f(r), after accounting for the distribution of m's, should not depend on m.

I think you need to weight the first f(r) (the one that does depend on m) by g(m), then integrate that over m to get the final f(r).
 
Thanks a lot for your reply. I agree with you that the final f(r), after accounting for the distribution of m, should not depend on m. Now shall i follow these steps

1. First find f(r) as a function of r and m where m is a random variable with the distribution g(m).
After that
2. Now int_{range of m}f(r)g(m)dm to get rid of m and find the final expression for f(r)

Are these steps correct?
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
2
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
969
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
Replies
1
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K