Wear. In a study by J. Zeng et al., three materials for making artificial teeth—Endura, Duradent, and Duracross—were tested for wear. Their results were published as the paper “In Vitro Wear Resistance of Three Types of Composite Resin Denture Teeth” (Journal of Prosthetic Dentistry, Vol. 94, Issue 5, pp. 453–457). Using a machine that simulated grinding by two right first molars at 60 strokes per minute for a total of 50,000 strokes, the researchers measured the volume of material worn away, in cubic millimeters. Six pairs of teeth were tested for each material. The data on the WeissStats CD are based on the results obtained by the researchers. At the 5% significance level, do the data provide sufficient evidence to conclude that there is a difference in mean wear among the three materials?
Use the technology of your choice to
a. Conduct a one-way ANOVA test on the data.
b. Interpret your results from part (a).
c. Decide whether presuming that the assumptions of normal populations and equal population standard deviations are met is reasonable.