Final answer:
To find the probability that a randomly chosen computer chip produced by this company is defective and was produced in St. Louis, we multiply the probability of a chip being produced in St. Louis by the probability of a chip being defective given that it was produced in St. Louis.
Step-by-step explanation:
To find the probability that a randomly chosen computer chip produced by this company is defective and was produced in St. Louis, we need to calculate the joint probability. First, we find the probability of a chip being produced in St. Louis, which is 45%. Then, we calculate the probability of a chip being defective given that it was produced in St. Louis, which is 0.85%. Finally, we multiply these two probabilities together to get the joint probability:
Joint Probability = Probability of St. Louis * Probability of Defective | St. Louis
Joint Probability = 0.45 * 0.0085
Joint Probability = 0.003825
Therefore, the probability that a randomly chosen computer chip produced by this company is defective and was produced in St. Louis is 0.3825%.