Use the data file Paint. (data below). A manufacturer of interior house paint is interested in determining if there is a difference in the hardness of paint (after it dries) among four different blends.

(a) Use the appropriate statistical test to determine if there is any difference in mean hardness among the different locations. Interpret using ? = .05.

(b) Include and interpret the confidence interval plot.

Data:

C1-T C2 Paint Hardness Blend 2 14.9 2 Blend 3 13.0 3 Blend 4 15.0 4 Blend 1 17.0 5 Blend 1 13.9 6 Blend 3 16.4 7 Blend 1 10.4 8 Blend 2 3.2 9 Blend 2 1.9 10 Blend 2 7.3 11 Blend 4 17.8 12 Blend 2 9.6 13 Blend 4 22.9 14 Blend 4 17.4 15 Blend 3 13.3 16 Blend 1 19.3 17 Blend 1 16.1 18 Blend 3 6.5 19 Blend 1 11.7 20 Blend 4 16.9 21 Blend 4 18.4 22 Blend 3 11.9 23 Blend 2 14.5 24 Blend 3 16.8