In an experiment, college students were given either four quarters or a $1 bill and they could either keep the money or spend it on gum. The results are summarized in the table.

Students given four quarters. 27 (purchased gum) 13 (kept the money) students given a $1 bill. 14 (purchased gum) 34 (kept the money)

Find the probability of randomly selecting a student who spent the money, given that the student was given four quarters.