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. Complete pans (a) through (c) below. Purchased Gum Kept the Money Q 16 28 Students Given Four Quarters Students Given a 31 Bill a. Find the probability of randomly selecting a student who spent the money, given that the student was given a $1 bill. The probability is 0.391 . (Round to three decimal places as needed.) b. Find the probability of randomly selecting a student who kept the money, given that the student was given a $1 bill. The probability is . (Round to three decimal places as needed.)