Mean of data set 1 = 1/5(43 + 42 + 56 + 62 + 72) = 275 / 5 = 55. Mean of data set 2 = 1/5(76 + 57 + 81 + 51 + 70) = 335 / 5 = 67. MAD of data set 1 = 1/5(|43 - 61| + |42 - 61| + |56 - 61| + |62 - 61| + |72 - 61|) = 1/5(18 + 19 + 5 + 1 + 11) = 54/5 = 10.8. MAD of data set 2 = |76 - 61| + |57 - 61| + |81 - 61| + |51 - 61| + |70 - 61| = 1/5(15 + 4 + 20 + 10 + 9) = 1/5(58) = 11.6. Mean to MAD ratio of set 1 = 55 / 10.8 = 5.1. Mean to MAD ratio of data set 2 = 67 / 11.6 = 5.8