Median vs. Second Quartile question

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Homework Help Overview

The discussion revolves around understanding the relationship between the median and the second quartile (Q2) in a set of numerical observations, specifically in the context of a list of income values.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the median and questions whether the median and the second quartile should be equal for non-grouped observations. Some participants clarify that the median and Q2 are indeed the same, while others reflect on their understanding of the definitions.

Discussion Status

Participants are exploring the definitions and calculations related to the median and quartiles. There is acknowledgment of correct calculations, but some confusion remains regarding the concepts, particularly about the nature of quartiles versus the median.

Contextual Notes

There is mention of a potential misunderstanding regarding the distinction between single values and ranges in statistical terms, specifically relating to quartiles and the inter-quartile range.

Mathman2013
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Homework Statement



Lets say I have a list of numbers.

income=[17000, 11000, 23000, 19999, 21000, 10000]

I sort them income_sorted=[10000, 11000, 17000, 19999, 21000, 23000]

Calculate med 2nd Quartile.

Homework Equations



Median_formula = (n+1)/2

The Attempt at a Solution



The second quartile and the median are most cases the same, so the median is 17000.

Then since there 6 observations.

I use the formula to Calculate the median and find that median = (6+1)/2 = 3.5

Meaning that the median is between the third and fourth number.

Find the average between those (17000+19999)/2 = 18500.

So my question aren't the median and 2.quartile suppose of a set of non-grouped observations suppose to equal each other? Or have I slept through statistics class?
 
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Mathman2013 said:
So my question aren't the median and 2.quartile suppose of a set of non-grouped observations suppose to equal each other? Or have I slept through statistics class?

You are correct in saying that the median and the second quartile (Q2) are the exact same thing. I believe you calculated the median correctly the second time (by averaging terms 3 and 4). What led you to say that the median is 17000?
 
[strike]I'm a bit rusty but I thought the median was a single value but a quartile was a range.[/strike]

I was wrong.
 
CWatters said:
[strike]I'm a bit rusty but I thought the median was a single value but a quartile was a range.[/strike]

I was wrong.
maybe you're thinking about the inter-quartile range?

Sorry, just saw the edit now.
 
Master1022 said:
maybe you're thinking about the inter-quartile range?

Sorry, just saw the edit now.
That was probably it.
 

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