The 4th term of a geometric sequence is 18, and the 10th term is 162. What is the 7th term?
The 10th term =
18 * r^6 = 162
r^6 = 162 / 18 = 9 take the 9th root
r= 9^(1/6)
The 7th term is
18 * r^3 =
18 * (9^(1/6))^3 =
18 * (9)^(1/2) =
18 * 3 =
54
