Question

13.Find the geometric mean of 3 and 7.

√21
2√6
2√7
21

14.Find the geometric mean of 18 and 8.

22
12
17
32

Answer 1

The geometric mean between two numbers a and b is the number x such that \(a:x\) is as \(x:b\). Written as fractions, \[\frac{a}{x} = \frac{x}{b}\] To find x, cross-multiply to get \[x^2 = ab\]and take the square root of both sides.