\(GM=(x_1 \times x_2 \times ... \times x_n)^{(1/n)}\) or \(GM=(x_1^{f_1} \times x_2^{f_2} \times ... \times x_n^{f_n})^{(1/\sum f_i)}\)
Find GM: 2, 4, 6
3.63
Try this one: 20020, 30080, 50086, 40130