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November 01, 2025, 10:27:29 am

Author Topic: Comparing LSRL with 3-median/mean line  (Read 1119 times)  Share 

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geoff_821

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Comparing LSRL with 3-median/mean line
« on: November 06, 2011, 09:58:22 pm »
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When would the Least Squares Regression Line, Three Median Line and Three Mean Line be appropirate to use, and why is one better than the other.

I know we need to use a three median line when there are "extreme values" present because it won't get influenced.
What about the others?

thatisanote

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Re: Comparing LSRL with 3-median/mean line
« Reply #1 on: November 06, 2011, 10:35:38 pm »
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don't think we need to compare the others (other than 3-med and least squares) but I'm interested to hear the thoughts of others.

3 median line is *less* influenced by outliers, though it can be influenced. (if the outlier is fixed up as it was an error in the data, it is possible that the median of a section could change)
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smithy16

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Re: Comparing LSRL with 3-median/mean line
« Reply #2 on: November 06, 2011, 10:40:05 pm »
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In what type of question would you say that one of the values found is an error? Least Squares or??

thatisanote

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Re: Comparing LSRL with 3-median/mean line
« Reply #3 on: November 06, 2011, 10:54:14 pm »
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In what type of question would you say that one of the values found is an error? Least Squares or??
nah you wouldn't say it but vcaa might.
e.g. it has the plot.
then it says 'it turns out that this value was an error and was actually meant to be xyz'

is it still an outlier?
or something like that
2010: Eco 46
2011: Eng 45 MMM 47 MFM 50 Phy 44 MUEP Comp Systems 5.5
2012: Stanford University :)

(selling SAT/american college books, pm me)