The cubic functions that "best" approximates: x:  -0.2,  1.3,   1.7,  3.2,   4.1,   4.6 y: 9.1, 17.5, 20.7, 25.4, 35.7, 51.2 cubic regression:  y = 1.207*x*x*x-6.3*x*x+12*x+11.6

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