11. The geometric mean of two numbers is 2. Find a number 4 times the other number.
Answers
Answer:
Example: What is the Geometric Mean of 2 and 18?
First we multiply them: 2 × 18 = 36
Then (as there are two numbers) take the square root: √36 = 6
In one line:
Geometric Mean of 2 and 18 = √(2 × 18) = 6
It is like the area is the same!
geometric mean 2x18 = 6x6
Example: What is the Geometric Mean of 10, 51.2 and 8?
First we multiply them: 10 × 51.2 × 8 = 4096
Then (as there are three numbers) take the cube root: 3√4096 = 16
In one line:
Geometric Mean = 3√(10 × 51.2 × 8) = 16
It is like the volume is the same:
geometric mean 10x51.2x8 = 16x16x16
Example: What is the Geometric Mean of 1, 3, 9, 27 and 81?
First we multiply them: 1 × 3 × 9 × 27 × 81 = 59049
Then (as there are 5 numbers) take the 5th root: 5√59049 = 9
In one line:
Geometric Mean = 5√(1 × 3 × 9 × 27 × 81) = 9
I can't show you a nice picture of this, but it is still true that:
1 × 3 × 9 × 27 × 81 = 9 × 9 × 9 × 9 × 9