Find the common ratio of the geometric sequence: - 320,80,-20,5, ...-320,80,-20,5, ... A. - 14-14 B. 1414 C. - 4 D. 4

Question

Sonny Bates

Mathematics

17 February, 06:45

Find the common ratio of the geometric sequence: - 320,80,-20,5, ...-320,80,-20,5, ... A. - 14-14 B. 1414 C. - 4 D. 4

+3

Answers (1)

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Jamar Rangel · Answer 1

I'm assuming the sequence is: - 320, 80, - 20, 5

Divide each term by the previous term to get the common ratio r

r = (term 2) / (term 1) = 80 / (-320) = - 1/4

r = (term 3) / (term 2) = - 20/80 = - 1/4

r = (term 4) / (term 3) = 5 / (-20) = - 1/4

No matter which term you pick (as long as it's not the first one) dividing it by the previous term leads to - 1/4 or - 0.25 as the common ratio

Answer: - 1/4

It seems like none of the answer choices have - 1/4 but it could be choice A was supposed to show "-1/4" instead of "-14"? Perhaps the division sign didn't show up for some reason?