SOLUTION: Find the indicated 25th partial sum of the arithmetic sequence. A<sub>#1</sub>=100, A<sub>#25</sub>=220, n=25

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Question 743327: Find the indicated 25th partial sum of the arithmetic sequence.
A#1=100, A#25=220, n=25
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
S#n = n%2F2(A#1 + A#n)

S#25 = 25%2F2(100 + 220)

S#25 = 25%2F2(320)

S#25 = 4000

Edwin