Question

find the geometric mean of 45,_,_,20

with solution please

Answer 1

let r be the common ratio

Answer 2

the next term is obtained by mutiplying the previous term by r, in this case, what follows 45 is 45r.

Answer 3

the previous term is equal to the next term divided r. therefore the term before 20 is 20/r

Answer 4

the geometric mean is \[\large \sqrt[4]{45\cdot 45r \cdot \frac{20}{r}\cdot 20}=\sqrt[4]{45^2\cdot 20^2}=30\]