Refer to Questionnaire color Problem 16.8 Explain how you would make the random assignments of supermarket parking lots to color in this single-factor study. Make all appropriate randomizations.
Problem 16.8
Questionnaire color. In an experiment to investigate the effect of color of paper (blue, green, orange) on response rates for questionnaires distributed by the "windshield method"
in supermarket parking lots, 15 representative supermarket parking lots were chosen . metropolitan area and each color was assigned at random [0 five of the lots. The response rates (in percent) follow. Assume that ANOYA model (16.2) is appropriate.
a. Prepare aligned dot plots of the data. Do the factor level means appear to differ? Does the variability of the observations within each factor level appear to be approximately the same for all factor levels?
b. Obtain the fitted values.
c. Obtain the residuals.
d. Obtain the analysis of variance table.
e. Conduct a test to determine whether or not the mean response rates for the three colors differ. Use level of significance a= .10. State the alternatives, decision rule, and conclusion. What is the P-value of the test?
f. When informed of the findings, an executive said: "See? I was right all along. We might as well print the questionnaires on plain white paper, which is cheaper." Does this conclusion follow from the findings of the study? Discuss.