Horwege Electronics inc. purchases TV picture tubes from four different suppliers. Tyson wholesale supplies 20% of the tubes, Fuji importers 30%, Kirkpatricks 25%, and parts inc. 25%. Tyson wholesale tends to have the best quality, as only 3% of its tubes arrive defective. Fuji importers' tubes are 4% defective, Kirkpatrick's 7%, and parts inc.'s are 6.5\% 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