Question: A manufacturer receives voltage regulators from three different companies, A, B, and C. The proportions of the voltage regulators coming from the three companies are 62%, 25%, and 13%, respectively. If 91% of the voltage regulators from A, 86% of those from B, and 79% of those from C meet the manufacturer’s expectations, what is the probability that a voltage regulator received by the manufacturer will meet its expectations? Use a tree diagram to help find the answer.