7 jobs such as A, B, C, D, E, F and G are allocated to X1, X2, X3, X4, X5, X6 and X7 machines in a business. Each machine does each job at different costs. Costs are given in the table below. In this case, determine which machine will do which job with the lowest cost? X1 X2 X3 X4 X3 A B D E F G 12 14 26 26 10 26 10 10 12 20 22 4 22 4 18 20 15 16 16 16 16 18 13 28 8 11 20 6 14 17 14 17 X6 11 12 7 8 4 8 4 X7 10 13 6 10 5 10 5 24 8 24