Question

If the geometric mean of a and 28 is 16 sqrt 7 find a

Answer 1

Answer:

a = 64

Step-by-step explanation:

The geometric mean of 2 numbers a and b is $\sqrt{ab}$ , then

$\sqrt{28a}$ = 16$\sqrt{7}$ ( square both sides )

28a = (16$\sqrt{7}$ )² = 1792 ( divide both sides by 28 )

a = 64

Answer 2

Answer:

a = 64

Step-by-step explanation:

The geometric mean for two numbers is given by :

GM = sqrt(ab)

16 sqrt(7) = sqrt(a*28)

Square each side

(16 sqrt(7))^2 = (sqrt(a*28))^2

256*7 = 28a

1792 = 28a

Divide each side by 28

1792/28 = 28a/28

64 = a