I am a beginner on calculating correlations and I would like to ask possibly a very simple question.

If I have two variables that I want to perform correlation on, and those variable are of unequal size, does this affect my correlation result?


  • $\begingroup$ The accepted answer to the duplicate asserts (correctly) that "This scaling [in the calculation of correlation] makes correlation invariant to changes in scale of the original variables..." $\endgroup$
    – whuber
    Dec 6, 2013 at 19:41
  • $\begingroup$ So if I have sample size of a=300,b=210 calculating the correlation of a with b, that's fine then, i.e. b doesn't have to be 300 as well? $\endgroup$
    – and_apo
    Dec 6, 2013 at 19:49
  • 1
    $\begingroup$ It now sounds that you are using "size" to mean "count." You cannot even begin calculating correlation on such data: they have to be paired. $\endgroup$
    – whuber
    Dec 6, 2013 at 19:50


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