The given sequence .
Apply nth term of a geometric sequence formula .
(Substitute
)
(Subtract power:
)
(Multiply:
)
(Rewrite
)
(Apply equal powers formula:
)
Apply 2nd term of a geometric sequence formula .
(Substitute
)
(Subtract power:
)
(Multiply:
)
Apply 3nd term of a geometric sequence formula .
(Substitute
)
(Subtract power:
)
(Evaluate power:
)
(Multiply:
)
The geometric means are 3, 9.