Chapter 15: A 23 factorial experiment.

Col 1: Levels for temperature, 160 (-) and 180 (+) degrees
Col 2: Levels for concentration, 20 (-) and 40 (+) percent
Col 3: 2 catalysts (A = - and B = +).   
Col 4: Results (yield in %'s).
        
             -    -    -     60    
             +    -    -     72    
             -    +    -     54
             +    +    -     68
             -    -    +     52
             +    -    +     83
             -    +    +     45
             +    +    +     80