9. As cited in an earlier example in class, an automatic shifting machine inserts mixed vegetables into a plastic bag. Experience revealed some packages were underweight and some overweight, but most of them had satisfactory weight as indicated below: Weight Underweight Satisfactory Overweight Probability 0.025 0.900 0.075 a. What is the probability of selecting three packages from the food processing line and finding all three of them underweight? b. What does this probability mean?