c. How does your decision change if John's usage habits change and now he uses the phone on average four hours a month, but will never use it more than five hours or less than three hours a month? 3. A service station owner receives tires from two sources, plant A and plant B. There is a probability of 60% that tires come from plant A. According to the store owner, 20% of all tires from plant A are defective and only 10% of tires from plant B are defective. a. Construct a probability tree for this problem b. Construct a probability table for this problem. c. Find the probability that a tire comes from plant A and is defective (HINT: find P(plant A and defective)). d. Given the you find a defective tire, what is the probability that it came from plant B