The following data on power consumption in electric furnace heats (kW consumed per ton of melted product) resulted from a 2^4 factorial experiment with three replicates. The factors were nature of roof (A, low/high), power setting (B, low/high), scrap used (C, tube/plate), and charge (D, 700 lb/1000 lb).
Treatment x_ijklm
(1) 865, 861, 799
a 946, 800, 840
b 776, 834, 746
ab 709, 789, 646
c 1017, 990, 954
ac 1028, 906, 977
bc 817, 783, 771
abc 829, 806, 691
d 991, 808, 650
ad 966, 976, 876
bd 702, 659, 650
abd 784, 700, 597
cd 922, 808, 868
acd 1055, 870, 907
bcd 798, 728, 700
abcd 753, 713, 715