Question

If the second term of a geometric sequence is 20 and the fourth term is 11.25, then what is the common ratio of the sequence?

I'm typically good at finding ratios if I'm given values that aren't spaced apart.

Answer 1

a_2 = 20
a_4 = 11.25

4-2 = 2

a_4 = ( a_2 )( r^2)
11.25 = (20) r^2

solve for r