(Assume all s are the same) Run an ANOVA, use.

b. If you reject Ho in a, do the Tukey test, use.

In a study of 90 patients on renal dialysis, Farhad Atassi (A-T) assessed oral home care practices. He collected data from 30 subjects who were in (1) dialysis for less than 1 year, (2) dialysis for 1 to 3 years, and (3) dialysis for more than 3 years. The following table shows plaque index scores for these subjects. A higher score indicates a greater amount of plaque. 1.00 2.00 1.50 2.00 1.00 1.83 2.17 2.00 2.67 1.00 1.83 1.33 2.00 1.83 2.17 2.00 2.83 3.00 2.00 2.17 2.33 (Continued) Group 1 Group 3 1.00 2.33 2.83 2.50 1.00 1.50 2.50 2.83 1.00 1.00 2.17 2.83 1.67 2.00 1.67 2.33 1.83 .83 2.17 2.33 2.17 .50 1.83 2.67 1.00 2.17 2.83 2.00 2.17 2.33 2.33 2.00 2.83 2.83 2.00 2.00 Source: Data provided courtesy of Farhad Atassi, DDS, MSC, FICOI. EXERCISES