The 2nd term in a geometic sequence is 20. the fourth term in the same sequence is 45/4 or 11.25. what is the common ratio in this sequence?

Let x be the value of the third term.

Since it's a geometric sequence, then:

Third term/Second term = Fourth term/Third term

x/20 = 11.25/x

Cross multiplication:

x^2 = 225

x = 15

So since the ratio is constant, then it is

x/20 = 15/20 = 3/4

So the common ratio is 3/4 or 0.75.