Horwege Electronics, Inc., purchases TV picture tubes from four different suppliers. Tyson Wholesale supplies 20 percent of the tubes, Fuji Importers 30 percent, Kirkpatricks 25 percent, and Parts, Inc., 25 percent. Tyson Wholesale tends to have the best quality, as only 3 percent of its tubes arrive defective. Fuji Importers' tubes are 4 percent defective, Kirkpatricks' 7 percent, and Parts, Inc. are 6.5 percent defective.
a. What is the overall percent defective?
b. A defective picture tube was discovered in the latest shipment. What is the probability that it came from Tyson Wholesale?