Research indicates that dietary copper deficiency reduces growth rate in rats. In a related study, Allen (A-65) assigned weanling male Sprague-Dawley rats to one of three food groups: copper-deficient (CuD), copper-adequate (CuA), and pair-fed (PF). Rats in the PF group were initially weightmatched to rats of the CuD group and then fed the same weight of the CuA diet as that consumed by their CuD counterparts. After 20 weeks, the rats were anesthetized, blood samples were drawn, and organs were harvested. As part of the study the following data were collected: Rat Diet Body weight (BW)(g) Heart weight (HW)(g) Liver weight (LW)(g) Kidney weight (KW)(g) Spleen weight (SW)(g) 1 253.66 0.89 2.82 1.49 0.41 2 400.93 1.41 3.98 2.15 0.76 3 CuD 355.89 1.24 5.15 2.27 0.69 4 404.70 2.18 4.77 2.99 0.76 6 397.28 0.99 2.34 1.84 0.50 7 421.88 1.20 3.26 2.32 0.79 8 PF 386.87 0.88 3.05 1.86 0.84 9 401.74 1.02 2.80 2.06 0.76 10 437.56 1.22 3.94 2.25 0.75 11 490.56 1.21 4.51 2.30 0.78 12 528.51 1.34 4.38 2.75 0.76 13 CuA 485.51 1.36 4.40 2.46 0.82 14 509.50 1.27 4.67 2.50 0.79 15 489.62 1.31 5.83 2.74 0.81 Rat Diet HW/BW (g/100 g) is there interaction effect