/* x = salinity(%),  y = nitrate level(um/l) */
data model;
        input x    y;
cards;
        35.45   30.00
        36.10   24.20
        35.74   25.40
        35.30   29.80
        35.40   30.70
        35.91   24.00
        35.48   28.50
        36.28   22.70
proc glm;
        model y = x / clm;
        output out = new      p = predict     r = resid;
proc plot;
        plot y * x;
        plot predict * x;
run;