smallest-circle problem question

Greetings all;

Say there contains 100 shoppes. Each shoppe has data about it such as how much sales they have, how many products they sell and so on. Say these shoppes are all close by.

Now, for enclosing the smallest circle question, is it possible to:

make a smallest circle around n of the shoppes with conditions.

for example, find the shoppes with most sales and highest sales for product A. then enclose the circle around the shoppes and weight the shoppes with highest sales more?

Merci!

[Walter Roberson]

... centroid and then the radius from there is the distance to the point furthest from the centroid ?