function [metryki, mHat, yHat ] = aprox(x, y, st)
    G = [];
    for k = 0:st
        G = [G x.^k];
    end

    attr = (G' * G)^(-1) * G' * y;
    mHat = attr;
    yHat = G * attr;

    modelAvg = mean(yHat);
    RSS = sum((y - yHat).^2);
    R2 = 1 - RSS/(sum((yHat-modelAvg).^2));
    metryki = [RSS, R2];
end