If x1,x2,x3,…x_1, x_2, x_3, \dotsx1,x2,x3,… is a geometric sequence such that ∑n=1∞xn=4\sum_{n=1}^{\infty} x_n = 4∑n=1∞xn=4 and ∑n=1∞xn3=647\sum_{n=1}^{\infty} x_n^3 = \frac{64}{7}∑n=1∞xn3=764, find the common ratio rrr.
r=12r = \frac{1}{2}r=21
r=14r = \frac{1}{4}r=41
r=23r = \frac{2}{3}r=32
r=34r = \frac{3}{4}r=43