SOLUTION: The sum of the first 4 terms of a geometric series is 15 and the sum of the next 4 terms is 240 determine the positive constant ratio

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Question 1109439: The sum of the first 4 terms of a geometric series is 15 and the sum of the next 4 terms is 240 determine the positive constant ratio
Answer by ikleyn(52788)   (Show Source): You can put this solution on YOUR website!
.
 =  = 15.       (1)    (given)

 =  = 240.    (2)    (given)


Now divide eq(2) by eq(1). You will get


 =  = 16.


The positive constant ratio is  r = 16^(1/4) = 2.

Solved.

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On geometric progressions, see introductory lessons
    - Geometric progressions
    - The proofs of the formulas for geometric progressions
    - Problems on geometric progressions
    - Word problems on geometric progressions
in this site.


Also,  you have this free of charge online textbook in ALGEBRA-II in this site
    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic "Geometric progressions".


Save the link to this textbook together with its description

Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson

into your archive and use when it is needed.



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