Question

In a geometric sequence, a4=7 and a6=28. Use the geometric mean to find the value of a5

Answer 1

if r is common ratio
r^2 = a6/a4 = 28/7 = 4

need any more help?

Answer 2

actually i'm not using the geometric mean to do this!!
geometric mean of a and b is sqrt(ab)

so if you plug in a = 7 and b = 28 you will get the value of a5

Answer 3

a5 = sqrt ( 7 *28)