A store sells four brands of tablets. The least expensive brand, B1, accounts for 40% of the sales. The other brands (in order of their price) have the following percentages of sales: B2, 30%; B3, 20%; and B4, 10%. The respective probabilities of needing repair during warranty are 0.10 for B1, 0.05 for B2, 0.03 for B3, and 0.02 for B4. A randomly selected purchaser has a tablet that needs repair under warranty. What are the four conditional probabilities of being brand Bi, i = 1, 2, 3, 4?