SOLUTION: find the common ratio of an infinite geometric series with first term 6 and with sum 7.5

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Question 82098This question is from textbook
: find the common ratio of an infinite geometric series with first term 6 and with sum 7.5 This question is from textbook

Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
find the common ratio of an infinite geometric series with first term 6 and with sum 7.5
The formula for finding the sume of an infinite series is: highlight%28S=a%2F%281-r%29%29, where S is sum, a is the first term, and r is the common ratio.
In your case, S=7.5 and a=6
7.5=6%2F%281-r%29
7.5%281-r%29=6%2F%281-r%29%2A%281-r%29
7.5-7.5r=6
7.5-7.5-7.5r=6-7.5
-7.5r=-1.5
-7.5r%2F-7.5=-1.5%2F-7.5
highlight%28r=1%2F5%29 or in decimal form highlight%28r=.2%29
Happy Calculating!!!!