SOLUTION: An arithmetic series has a sum of -823.5 with 27 terms. The first term is 5. Determine t27

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Question 1162998: An arithmetic series has a sum of -823.5 with 27 terms. The first term is 5. Determine t27
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
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It is a TWIN problem to the problem solved under this link

https://www.algebra.com/algebra/homework/Sequences-and-series/Sequences-and-series.faq.question.1162999.html


Having this TEMPLATE in front of view, solve the given problem BY THE SAME WAY on your own.



Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The sum of the terms in an arithmetic sequence is the number of terms, multiplied by the average of the terms.

In an arithmetic sequence, the average of all the terms is the average of the first and last terms.

So in this problem, if x is the 27th (last) term,

-823.5+=+27%28%285%2Bx%29%2F2%29
-1647+=+27%285%2Bx%29
x%2B5+=+-1647%2F27+=+-61
x+=+-66

ANSWER: The 27th term is -66.