Question

PLEASE HELP MEEEEE

Two numbers, 4 and a, have a geometric mean of 12.Find the value of a.


Two numbers, 3 and a, have a geometric mean of 9.Find the value of a.

Answer 1

a = 36 and a = 27

Explanation:

The geometric mean of two numbers is the square root of the product of the two numbers.

Say for example we have the numbers x and y, the geometric mean z is mathematically;

z = √xy

For the first question, our z is 12, x and y are 4 and a respectively.

12 = √4a

square both sides

144 = 4a

a = 144/4

a = 36

For the second question

z is 9, x and y are 3 and a respectively

9 = √3a

square both sides

81 = 3a

a = 81/3

a = 27