& z 0.90 0.80 0.70 0.60 0.50 
-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 
-2 -3 -4 -5 -6 -7 -8 -9 -10 -11 
-3 -4 -5 -6 -7 -8 -9 -10 -11 -12 
x 100 200 300 400 500 600 700 800 
y 150 250 350 450 550 650 750 850 
z 200 300 400 500 600 700 800 900