The nth term of a geometric sequence can be calculated as:
[tex]t_n=t_1\cdot r^{n-1}[/tex]
Where t1 is the initial term and r is the common ratio.
We are given the general term of a geometric sequence:
[tex]t_n=-4\cdot\left(\frac{7}{8}\right)^{n-1}[/tex]
When comparing both equations, we know that a1 = -4, r = 7/8
Answer: C 7/8
