Math CentralQuandaries & Queries


Question from Sid, a student:


Given below is the problem that I am facing:
I have N data points in m-dimensional space. I know the mean euclidean distance of the points from one given point (say the origin). Now I wish to find the mean Euclidean distance of the N points from another given point. How can i do this without knowing the values of the N points and only knowing the 2 origin points and the mean distance from one of the origin points ?


If I understand you correctly the following is a special case of what you're asking:

take 3 points on a unit circle in the plane, centred at the origin (0,0), you want the mean distance from (1,0). Clearly this is impossible witout further information.


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