SOLUTION: A gp has 8 terms it's first and last terms are 0.3 and 83.4 calculate the common ratio

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Question 1204307: A gp has 8 terms it's first and last terms are 0.3 and 83.4 calculate the common ratio
Found 2 solutions by josgarithmetic, MathLover1:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
0.3, ?, ?, ?, ?, ?, ?, 83.4

Let common ratio be r.
0.3%2Ar%5E7=83.4----------can you do the rest?


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Quick use of calculator tells 2.2343, approximately.

Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

geometric sequence nth term formula is:
+a%5Bn%5D=a%5B1%5D%2Ar%5E%28n-1%29

given:
+a%5B1%5D=0.3
+a%5B8%5D=83.4
plug it in formula above an solve for r
+83.4=0.3%2Ar%5E%288-1%29
+83.4=0.3%2Ar%5E7
+r%5E7=83.4%2F0.3
+r%5E7=278
+r=root%287%2C278%29 => exact solution, your answer

and, your formula is:
+a%5Bn%5D=0.3%2A%28root%287%2C278%29%29%5E%28n-1%29