When commercial aircraft are inspected, wing cracks are reported as nonexistent, detectable, or critical. The history of a particular fleet indicates that 70% of the planes inspected have no wing cracks, 25% have detectable wing cracks, and 5% have critical wing cracks. Five planes are randomly selected. Find the probability that a one has a critical crack, two have detectable cracks, and two have no cracks. b at least one plane has critical cracks.

Week 5 & 6: Probability 4 October 2016, 11 October 2016 Basic Statistics for Research Professor HK Dong Wendy Liu Probability – numerical measure of the likelihood an event will occur Lies between 0 and 1 Sum of all probabilities of all possible outcomes is 1 Method 1: approximation Empirical frequency obtained by experimentation Method 2: actual calculation ...