Find the Probability of Joint PDF X and Y with Easy Calculation

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    Joint Pdf
In summary, a joint PDF (probability density function) is a mathematical function that describes the probability of two or more random variables occurring simultaneously. To find the probability of a joint PDF for X and Y, you need to integrate the function over the region of interest. The probability of a joint PDF cannot be greater than 1, and it can be used to make predictions by calculating the likelihood of certain outcomes for multiple variables. This differs from a marginal PDF, which describes the probability of a single variable occurring.
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sjaguar13
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Given this joint PDF of X and Y:
Code:
X\Y	1	2
0 	0.1	0.3
1	0.05	0.1
2	0.2	0.25

So:
P(X = 1| X+Y=2) = 1/2?
P(X <= 1 and Y <= 2) = 1/3?
 
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...Anyone?
 
  • #3
sjaguar13 said:
Given this joint PDF of X and Y:
Code:
X\Y	1	2
0 	0.1	0.3
1	0.05	0.1
2	0.2	0.25

So:
P(X = 1| X+Y=2) = 1/2?
P(X <= 1 and Y <= 2) = 1/3?

I don't get either of those. How did you get those answers?
 

What is a joint PDF?

A joint PDF (probability density function) is a mathematical function that describes the probability of two or more random variables occurring simultaneously. It is used to calculate the likelihood of a specific outcome for multiple variables.

How do you find the probability of a joint PDF for X and Y?

To find the probability of a joint PDF for X and Y, you need to integrate the function over the region of interest. This means that you must determine the bounds of the integral based on the given values for X and Y. Once the integral is solved, the resulting value is the probability of X and Y occurring together.

Can the probability of a joint PDF be greater than 1?

No, the probability of a joint PDF cannot be greater than 1. This is because the total probability of all possible outcomes must equal 1. If the probability of X and Y occurring together is greater than 1, it would violate this rule.

What is the difference between a joint PDF and a marginal PDF?

A joint PDF describes the probability of two or more variables occurring together, while a marginal PDF describes the probability of a single variable occurring. The marginal PDF is found by integrating the joint PDF over all possible values of the other variables.

How can I use joint PDF to make predictions?

Joint PDFs can be used to make predictions by calculating the probability of certain outcomes for multiple variables. This can be helpful in decision-making or risk analysis, as it allows you to estimate the likelihood of certain events occurring based on the given data.

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