An investigation was conducted to determine the source of reduction in the yield of a certain chemical product. It was known that the loss in yield occurred in the mother liquor, that is, the material removed at the filtration stage. It was thought that different blends of the original material might result in different yield reductions at the mother liquor stage. The following are the percent reductions for 3 batches at each of 4 preselected blends:
Blend 25.6-252-20.8-31.6- 24.3 28.6 26.7 29.8 27.9 247 222 34.3
a. Perform the analysis of variance at the α :0 05 levels of significance
b. Use Duncan's multiple range test to determine which blends differ c. Do part (b) using Tukey's test