A Research Project Studied the Physical Properties of Wood Materials

Multiple Choice

A research project studied the physical properties of wood materials constructed by bonding together small flakes of wood.The two factors considered were the size of the flakes and species of tree.The sizes of the flakes were S1: 0.15 inches by 2 inches and S2: 0.25 inches by 2 inches,and the species of tree used were aspen,birch,and maple.For each combination of flake size and tree species,three samples of wood material were constructed.For each sample,the physical property measured was the tension modulus of elasticity in the direction perpendicular to the alignment of the flakes,in pounds per square inch (psi) . The table below gives the means for the different size-species groups: For these data,a two-way ANOVA was run and the partial ANOVA table is given below. In the ANOVA table,the test for the main effect of size has a P-value of 0.613.What does this indicate?

A) The effect of particle size probably varies considerably for the different species.
B) For about 61.3% of the samples,there was a difference in the effect of particle size.
C) For about 61.3% of the samples,there was no difference in the effect of particle size.
D) None of the above