Example 17.5.1 test C*beta=d0 

speed={38.8, 31.5, 10.6, 16.1,  7.7, 8.3,  8.5,  11.1,  8.6, 11.1,
        9.8,  7.8, 31.8, 31.6, 34.0, 28.9, 28.8, 10.5, 12.3, 13.2,
       11.4, 11.2, 10.3, 11.4};
density={20.4, 27.4, 106.2, 80.4, 141.3, 130.9, 121.7, 106.5,
        130.5, 101.1, 123.9, 144.2, 20.9, 30.8, 26.5, 35.7, 30.0,
        106.2, 97.0, 90.1, 106.7, 99.3, 107.2, 109.1};