Insert three geometric means between 1 and 81.

Answer 1

1 , r , r^2 , r^3 , 81

so r/1 = 81/r^3
r^4 = 81
r = ± 3

the 3 geometric means could be

3, 9 , and 27
or
-3 , 9, and -27

Answer 2

Need improvement

Answer 3

techari gaide?