Disks of polycarbonate plastic from a supplier are an- alyzed for scratch and shock resistance. The results from 100 disks are summarized as follows: scratch resistance shock resistance high low high 70 9 low 16

(a) If a disk is selected at random, what is the probability that its scratch resistance is high and its shock resistance is high?

(b) If a disk is selected at random, what is the probability that its scratch resistance is high or its shock resistance is high?

(c) Consider the event that a disk has high scratch resistance and the event that a disk has high shock resistance. Are these two events mutually exclusive?