In a probability experiment, Eric flipped a coin 39 times. The coin landed on heads 26 times. What is the ratio of heads to tails in this experiment?

The number of tails in this experiment is 39 - 26 = <<39-26=13>>13

Therefore, the ratio of heads to tails in this experiment is 26/13 = <<26/13=2>>2/1 or 2:1. Answer: \boxed{2:1}.