1 Answer

Shaphan · Answer 1 · 2022-12-22T07:12:40+0000

Answer:

r = 6

Explanation:

Given

a = 3 --- First, term

T_4 = 648 --- Fourth term

Required: Determine the common ratio

The nth term of a GP is

$T_n = ar^{n-1$

Substitute 4 for n

$T_4 = ar^{4-1$

$T_4 = ar^{3$

Substitute 648 and 3 for T4 and 3 respectively.

$648 = 3 * r^{3$

r^3 = 216

Take cube roots of both sides

$r =\sqrt[3]{216}$

r = 6

The common ratio is 6

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