question_answer

The weighted arithmetic mean of the first n natural numbers whose weights are equal to the corresponding numbers is given by

A)  \[\frac{1}{2}(n+1)\]       

B)         \[\frac{1}{2}(n+2)\]

C)  \[\frac{1}{3}(2n+1)\]      

D)         \[\frac{1}{3}n(2n+1)\]