An automobile manufacturer obtains the microprocessors used to regulate fuel consumption in its automobiles from three microelectronic firms: A, B, and C. The quality-control department of the company has determined that 2% of the microprocessors produced by firm A are defective, 5% of those produced by firm B are defective, and 3.5% of those produced by firm C are defective. Firms A, B, and C supply 45%, 30%, and 25%, respectively, of the microprocessors used by the company. What is the probability that a randomly selected automobile manufactured by the company will have a defective microprocessor?