Analysis:
Ho: u1=u2=u3=u4
Ha: u item1=u item2=u item 3=………=u item 20 Anova: Two-Factor Without Replication | | | | | | | | | SUMMARY | Count | Sum | Average | Variance | | Milk | 4 | 10.53 | 2.6325 | 0.017492 | | Cheese | 4 | 11.26 | 2.815 | 0.789167 | | whipped Cream | 4 | 8.03 | 2.0075 | 0.197092 | | Gallon of Ice Cream | 4 | 22.46 | 5.615 | 0.229167 | | Eggs | 4 | 9.32 | 2.33 | 0.3984 | | Butter | 4 | 10.57 | 2.6425 | 0.192358 | | Bread | 4 | 7.04 | 1.76 | 1.961533 | | Pancake Mix | 4 | 17.46 | 4.365 | 14.08917 | | Corn Flakes | 4 | 9.47 | 2.3675 | 1.223358 | | Bag of Flour | 4 | 14.84 | 3.71 | 8.3936 | | Peanut Butter | 4 | 11.67 | 2.9175 | 0.539692 | | Maple Syrup | 4 | 8.54 | 2.135 | 0.406767 | | Potato Chips | 4 | 11.49 | 2.8725 | 0.555025 | | Salad Dressing | 4 | 6.36 | 1.59 | 0.186667 | | Box of Pasta | 4 | 4.73 | 1.1825 | 0.025425 | | Lettuce | 4 | 5.35 | 1.3375 | 0.113025 | | 1 pound of Tomato | 4 | 3.55 | 0.8875 | 0.021358 | | Bag of Potatoes | 4 | 6.26 | 1.565 | 0.089167 | | Package of Turkey | 4 | 15.96 | 3.99 | 2 | | Orange Juice | 4 | 14.38 | 3.595 | 1.925367 | | | | | | | | REAMS | 20 | 66.75 | 3.3375 | 4.150514 | | WALMART | 20 | 53.16 | 2.658 | 2.965606 | | SMITH | 20 | 44.79 | 2.2395 | 1.763889 | | HORMONE | 20 | 44.57 | 2.2285 | 1.130519 | | | | | | | | | | | | | | ANOVA | | | | | | | Source of Variation | SS | df | MS | F | P-value | F crit | Rows | 106.4233 | 19 | 5.601224 | 3.810958 | 4.61E-05 | 1.771972 | Columns | 16.28469 | 3 | 5.428231 | 3.693257 | 0.01685 | 2.766438 | Error | 83.77678 | 57 | 1.469768 | | | | | | | | | | | Total | 206.4847 | 79 | | | | | | | | | | | |
Since the P-values are very small on both row and columns, we will reject the Ho and Ha, blocking is necessary.

Appendix | REAMS | WALMART | SMITH | HORMONE | Milk | 2.55 | 2.79 | 2.69 | 2.5 | Cheese | 3.99 | 2.99 | 1.99 | 2.29 | whipped Cream | 2.03 | 2.59 | 1.89 | 1.52 | Gallon of Ice Cream | 4.99 | 5.99 | 5.49 | 5.99 | Eggs | 2.75 | 1.39 | 2.59 | 2.59 | Butter | 2.99 | 2.79 | 2 | 2.79 | Bread | 3.79 | 0.78 | 0.88 | 1.59 | Pancake Mix | 9.99 | 2.69 | 2.49 | 2.29 | Corn Flakes | 3.99 | 1.99 | 1.99 | 1.5 | Bag of Flour | 2.99 | 7.99 | 1.87 | 1.99 | Peanut Butter | 3.99 | 2.79 | 2.39 | 2.5 | Maple Syrup | 2.99 | 1.87 | 1.49 | 2.19 | Potato Chips | 3.99 | 2.5 | 2.5 | 2.5 | Salad Dressing | 1.99 | 1.59 | 0.99 | 1.79 | Box of Pasta | 0.99 | 1.17 | 1.38 | 1.19 | Lettuce | 0.88 | 1.39 | 1.39 | 1.69 | 1 pound of Tomato | 0.99 | 0.89 | 0.99 | 0.68 | Bag of Potatoes | 1.49 | 1.99 | 1.29 | 1.49 | Package of Turkey | 3.99 | 2.99 | 5.99 | 2.99 | Orange Juice | 5.39 | 3.99 | 2.5 | 2.5 |