50 A new dental bonding agent. Refer to the Trends in Biomaterials & Artificial Organs (Jan. 2003) study of a new bonding adhesive for teeth, presented in Exercise 30.

A completely randomized design was used to compare the mean breaking strengths of teeth bonded for three different bonding times: 1 hour, 24 hours, and 48 hours. The sample mean breaking strengths were x1 hour = 3.32 Mpa,

x24 hours = 5.07 Mpa, and x48 hours = 5.03 Mpa. Using an experimentwise error rate of .05, Tukey’s method detected no significant difference between the means at 24 and 48 hours; however, the mean at 1 hour was found to be significantly smaller than the other two means.

a. Illustrate the results of the multiple comparisons of means by ordering the sample means and connecting means that are not significantly different.

b. What practical conclusions can you draw from the analysis?

c. Give a measure of reliability (i.e., overall confidence level) for the inferences drawn in part b.