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excelrandomnumbers

Generate N random numbers whose sum is a constant K - Excel

How can I generate those numbers in Excel.

I have to generate 8 random numbers whose sum is always 320. I need around 100 sets or so. http://en.wikipedia.org/wiki/User:Skinnerd/Simplex_Point_Picking. Two methods are explained here.

Or any other way so I can do it in Excel.

Solution

  • You could use the RAND() function to generate N numbers (8 in your case) in column A.

    Then, in column B you could use the following formula B1=A1/SUM(A:A)*320, B2=A2/SUM(A:A)*320 and so on (where 320 is the sum that you are interested into).

    So you can just enter =RAND() in A1, then drag it down to A8. Then enter =A1/SUM(A:A)*320 in B1 and drag it to B8. B1:B8 now contains 8 random numbers that sum up to 320.

    Sample output:

    enter image description here