The next table gives data for a 2 * 2 factorial experiment with two observations per factor-level combination.

a. Identify the treatments for this experiment. Calculate and plot the treatment means, using the response variable as the y-axis and the levels of factor B as the x-axis. Use the levels of factor A as plotting symbols. Do the treatment means appear to differ? Do the factors appear to interact?

b. Use the computational formulas in Appendix C to create an ANOVA table for this experiment.

c. Test to determine whether the treatment means differ at the α = .05 level of significance. Does the test support your visual interpretation from part a?

d. Does the result of the test in part b warrant a test for interaction between the two factors? If so, perform it using α = .05. 

e. Do the results of the previous tests warrant tests of the two factor main effects? If so, perform them using α = .05. Yes.

f. Interpret the results of the tests. Do they support your visual interpretation from part a?

g. Given the results of your tests, which pairs of means, if any, should be compared?

Transcribed Image Text:

Factor A Level 1 2 Factor B 1 29.6, 35.2 12.9, 17.6 2 47.3, 42.1 28.4, 22.7