Expected value of the log of a uniform distribution

In summary, the expected value of the log of a uniform distribution can be calculated by using the formula 1/(b-a) * integral from a to b of ln(x), where a and b are the lower and upper bounds of the uniform distribution. This method takes into account the first moment of the distribution and provides the correct value for expected value and variance.
  • #1
Gekko
71
0

Homework Statement



How to calculate the expected value of the log of a uniform distribution?

Homework Equations



E[X] where X=ln(U(0,1))

The Attempt at a Solution



integral from 0 to 1 of a.ln(a) da where a = U(0,1)
= -1/4

However I know the answer is -1
 
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  • #2
Why do you integrate over [tex]a \cdot ln(a)[/tex]?
 
  • #3
Yes, that's not right I see.

I used this approach instead. To find the first moment of a uniform distribution it is:

1/(b-a) * integral from a to b of x

In this case it is

1/(b-a) * integral from a to b of ln(x)

Is this ok?

This approach calculates the correct value for expected value and variance
 
Last edited:
  • #4
Yup, that's the correct method.
 

What is the expected value of the log of a uniform distribution?

The expected value of the log of a uniform distribution is the average of all the possible outcomes of the log of a uniform distribution. It is a measure of the central tendency of the distribution and represents the average value that can be expected from a random sample.

How is the expected value of the log of a uniform distribution calculated?

The expected value of the log of a uniform distribution can be calculated using the formula E(log(X)) = (b-a)/2, where a and b are the lower and upper bounds of the uniform distribution.

Does the expected value of the log of a uniform distribution change with different bounds?

Yes, the expected value of the log of a uniform distribution will change with different bounds. The larger the difference between the bounds, the larger the expected value will be. Similarly, a smaller difference between the bounds will result in a smaller expected value.

What is the significance of the expected value of the log of a uniform distribution?

The expected value of the log of a uniform distribution is an important metric in probability theory and statistics. It helps in understanding the central tendency of a distribution and can be used to make predictions and decisions based on the average value.

Can the expected value of the log of a uniform distribution be negative?

Yes, the expected value of the log of a uniform distribution can be negative. This can happen if the lower bound of the distribution is greater than 1. In such cases, the log of a uniform distribution will result in negative values, which will affect the overall expected value.

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