Posted by Mona on .
The geometric mean x of two numbers is the positive value of x that satisfies the proportion a/x =x/b, where a and b are given. Find the geometric mean of 16 and 9.

Geometry8th gr 
Reiny,
16/x = x/9 , crossmultiply
x^2= 144
x = √144 = 12
check:
16/12 = 4/3
12/9 = 4/3 
Geometry8th gr 
Mona,
Thanks. So the geometric mean for 16 and 9 is 4/3?

Geometry8th gr 
Reiny,
NOOO, the geometric mean is 12
I merely showed that 12 is correct
and satisfied your given proportion
a/x = x/b
the 3 numbers are:
16 , 12 , 9 , with 12 as the geometric mean 
Geometry8th gr 
Mona,
Oh okay...thanks.