Question

Two geometric means are inserted between 4 and 864 so the four numbers form a geometric sequence. What are these two numbers ?

Answer 1

24 and 144

Explanation:

a = 4

t4 = 864

864 = 4*r^(4 - 1) divide by 4

216 = r^3 Take the cube root of 216

6 = r

Note you can find the cube root of any number by using your calculator.

• 216
• y^x or x^y or ^
• 0.333333333333
• =
• 5.99999999 which rounded is 6

t2 = a * r^(2 - 1)

t2 = 4 * 6^1

t2 = 24

=================

t3 = a*r^(3 -1)

t3 = 4 * 6^2

t3 = 4 * 36

t3 = 144

Answer

24 and 144