Respuesta :

Given:

The number 12 is the geometric mean between 3 and a number x.

We need to determine the value of x.

Value of x:

Since, we know that the geometric mean is the square root of the product of two numbers.

Hence, we have;

[tex]Geometric \ mean= \sqrt{a \times b}[/tex]

where a and b are two positive numbers.

Substituting Geometric mean = 12, a = 3 and b = x, we get;

[tex]12= \sqrt{3 \times x}[/tex]

Squaring on both sides, we get;

[tex]12^2=3 \times x[/tex]

[tex]144=3\times x[/tex]

Dividing both sides of the equation by 3, we have;

[tex]48=x[/tex]

Thus, the value of x is 48.