65. Four types of mortars ordinary cement mortar

(OCM), polymer impregnated mortar (PIM), resin mortar (RM), and polymer cement mortar (PCM)

were subjected to a compression test to measure strength (MPa). Three strength observations for each mortar type are given in the article Polymer Mortar Composite Matrices for Maintenance-Free Highly Durable Ferrocement (J. Ferrocement, 1984: 337—345) and are reproduced here. Construct an ANOVA table. Using a .05 signi cance level, determine whether the data suggests that the true mean strength is not the same for all four mortar types.

If you determine that the true mean strengths are not all equal, use Tukey s method to identify the signi cant differences.

OCM 32.15 35.53 34.20 PIM 126.32 126.80 134.79 RM 117.91 115.02 114.58 PCM 29.09 30.87 29.80