The is the best measure of central tendency when there are extreme values in the distribution.

I think Theodosius the best measure. The outliers will not effect the measure. If you use mean, you add all the data points and divide by the number of data points. The extremes will skew the data. If you use mode, that may work also. You find the data that occurs most often.

We know that the radius is 15 feet So,

What we do is this:

(Circumference) 3.14× twice the radius. ( 15+15) 
3.14×30=94.2

So the Correct answer is 94.2