SOLUTION: The third term of a geometric sequence is 75. The fifth term is 27. Find the first term.

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Question 828197: The third term of a geometric sequence is 75. The fifth term is 27. Find the first term.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The third term of a geometric sequence is 75. The fifth term is 27. Find the first term.
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a*r^2 = 75
a*r^4 = 27
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Divide and solve for "r":
r^2 = 27/75
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r = (27/75)^(1/2) = 0.6
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Solve for "a"::
a*r^2 = 75
a = 75/(0.6)^2 = 208 1/3
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Cheers,
Stan H.
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