Question

A study was conducted to evaluate the performance of several cool season grasses for the winter overseeding of golf greens in North Florida. In the study, a golf ball was rolled down an inclined plane, to induce a constant initial velocity, and then the distance traveled by the ball on the green was measured. This distance can be influenced by the slope of the green, and so the study was conducted in four randomized complete blocks; each block contained five plots with similar slopes. In each case, the ball was rolled down the sople of the plot. Five cultivars (A: Pennfine rye grass; B: Dasher rye grass; C: Regal rye grass; D: Marvel green supreme; E: Barry rye grass) were randomly assigned to the five plots in each block. For five balls rolled down the ramp on each plot, the average distances (m) from the base of the ramp to the stopping point are as follows:

Block	Variety A	B	C	D	E
1	2.764	2.568	2.506	2.612	2.238
2	3.043	2.977	2.533	2.675	2.616
3	2.600	2.183	2.334	2.164	2.127
4	3.047	3.028	2.895	2.724	2.697

Use minitab and show steps.

a) Write a model for the data; explain all the terms in your model.

b) Set up the ANOVA table and draw conclusions based on appropriate F-tests.

c) Perform pairwise multiple comparison of the treatment means using Duncan’s procedure at the 0.05 level.

Answer 1

b)

From the analysis table, we can conclude that both the velocity and block have the significant effect on the distance at 0.05 level of significance. That is at least one velocity has a different effect on distance from remaining velocity. Similarly, at least one block has a different effect on distance from remaining blocks.