How Do You Calculate Mean and Median from a Joint Distribution Table?

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Discussion Overview

The discussion revolves around calculating the mean, median, and standard deviation from a joint distribution table representing hourly wages and years of education. Participants seek clarification on how to interpret the table and perform the calculations for both variables.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant expresses confusion about how to find the mean, median, and standard deviation from the joint distribution table.
  • Another participant suggests calculating the mean by summing all values and dividing by the number of items, and describes a method for finding the median.
  • A participant points out the arrangement of the table, clarifying that the values for Y are along the top and those for X are along the side, and questions how to derive means and medians for each variable.
  • Further clarification is requested on whether the mean should be calculated for fixed values of X or Y.
  • One participant shares their calculations for the means of X and Y using marginal probabilities, but questions how to find the median.
  • Another participant asks about the source of specific probabilities used in the calculations.
  • A participant suggests that the statistics for X and Y should be considered independently, prompting a question about the underlying inquiry.

Areas of Agreement / Disagreement

Participants do not reach a consensus on how to approach the calculations, and multiple competing views on the interpretation of the joint distribution table and the calculations remain evident.

Contextual Notes

There are unresolved questions regarding the definitions of the means and medians being sought, as well as the specific probabilities used in calculations. The discussion reflects uncertainty about the correct approach to analyzing the joint distribution.

Who May Find This Useful

This discussion may be useful for individuals interested in statistics, particularly those looking to understand joint distributions and how to derive statistical measures from them.

Economics2012
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Joint Distribution (Means,Medians...) PLEASE HELP!

Hi, I'm wondering if somebody could help me understand this...
If you have a joint distribution with

Hourly Wage (Y)
Years of Education (X) 9 15 30
10 0.07 0.02 0.01
14 0.10 0.30 0.10
16 0.02 0.10 0.28Sorry the 0.07,0.10 and 0.02 are under the 9 and the 0.02,,0.30 and 0.10 are under 15 etc.

How would you find the mean,median or st dev?

I'm so very confused with this stuff?

Any help would be greatly appreciated?
 
Last edited:
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It is not clear what you want. If you want the mean of everything, just add up all the numbers and divide by the number of items (9). Ti get the median, arrange them in order and take the middle number. To get the variance, first get the average of the squares and then subtract the square of the mean.
 


Well see the table looks a bit odd there Y is along the top and X is along the left hand side.
9,15 and 30 are belong to Y and 10,14 and 16 are belong to X. then the numbers are in the table.
It says find the means, medians and st devs of X and Y.
I did what you said before I posted here, but that would be the whole table wouldn't it?
I'm confused as in how you get one for each, is that what this means?
 


You need to clarify what you want the mean, etc. of. Do you want it over X for fixed Y (3 answers) or over Y for fixed X (also 3 answers) or something else?
 


I found the x and y mean...
u=Ep(x)x

ux=(10)(0.1)+(14)(0.5)+)(16)(0.4) = 14.4 -> mean for X by using the marginals
uy= same procedure I got 21.61.

Do you know how you get the median for this, if you understand what I mean?
 


Economics2012 said:
I found the x and y mean...
u=Ep(x)x

ux=(10)(0.1)+(14)(0.5)+)(16)(0.4) = 14.4 -> mean for X by using the marginals
uy= same procedure I got 21.61.

Do you know how you get the median for this, if you understand what I mean?

Where did 0.1, 0.5, and 0.4 come from?
 
Last edited:


Adding the x's across and then you get the y's by adding down.
 


It looks like you are asking for the statistics of X independent of Y and the statistics of Y independent of X. ux is then the average wage and uy is the average years. What is the underlying question?
 

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