prob8 := [[-1.9, -4.7], [-.8, 1.2], [.1, 2.8], [1.4, -1.2], [1.8, -3.5]];
prob9 := [[1.02, -4.30], [1.00, -2.12], [.99, .52], [1.03, 2.51], [1.00, 3.34]
, [1.02, 5.30]];