A steel ball has a diameter of 1.6 centimeters what is the volume of this steel ball round your anwser to the nearest tenth if necessary (AHHH HELP ME PLEASE)

What is the sum of the geometric series in which a1 = 7, r = 3, and an = 1,701? hint: cap s sub n equals start fraction a sub one left parenthesis one minus r to the power of n end power right parenthesis over one minus r end fraction comma r ≠ 1, where a1 is the first term and r is the common ratio