use the geometric mean to find the 7th term in a geometric sequence if the 6th term is 12 and the 8th term is 27. a.18 b.19.5 c.20 d.17

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A geometric sequence is when numbers in sequence have a common ratio. To solve this problem, we need for the geometric ratio for the sequence. Using the equation: an=a1r^n-1 where is an is the number at an n term, r is the ratio and a1 is the first number of the sequence. From the given numbers, 12 = a1 r^5 27 = a1r^7  From the equations above, a1 = 128/81 r = 3/2 Therefore, the 7th term is: an = (128/81) (3/2)^6 an = 18

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