Consider the following classroom activity. Suppose the floor consists of square tiles 9 in. on each side. The players will toss a circular disk onto the floor. If the disk comes to rest on the edge of any tile, the player loses \(\$ 1\). Otherwise, the player wins \(\$ 1\). What is the probability of winning if the disk is:

a. a dime

b. a quarter

c. a disk with a diameter of 4 in.

d. Now, the real question: What size should the disk be so that the probability that the player wins is 0.45 ?