Someone help please!

Will give brainliest sum of arithmetic series (sigma notation) find the numerical answer to the summation given below. (image shown below)

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

{0,1,2,3,4,5,6,20,21,22,23,24,25} the distribution is considered to be: skewed the right, skewed the left, not skewed?