Question

What is the geometric mean of 3 and 15?. Answer. .A] 22.5. B] 45. C] 3 radical 5. D] 5 radical 3.

Answer 1

3/x = x/15 
45 = x^2 
√9 * √5 = √x^2 
3√5 = x 
or 
x = 3√5