Answer:

r = 0.2

Step-by-step explanation:

a1 = 25, 625; a4 = 205; n = 4; r = ?

an = a1 r^n-1

205 = 25, 625 r^4 - 1

205 = 25, 625 r^3

205/25, 625 = 25, 625 r^3/25, 625

3√0.008 = 3√r^3

r = 0.2

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