Students recruited at the cafeteria at Hope College were blindly given a single Skittles® candy to put in their mouth. They were told the five possible flavors and then were asked which flavor they had. Of the 154 healthy students tested, 78 gave the correct answer. Of the 118 students tested who had stuff y or runny noses, 44 gave the correct answer.
a. Was this an observational study or an experiment? How are you deciding?
b. What are the observational units?
c. What are the variables recorded? For each variable, identify the type of the variable (categorical or quantitative) and the role of the variable (explanatory or response).
d. Did the study involve random sampling, random assignment, both, or neither? How are you deciding?
e. An appropriate analysis of the data shows that there is strong evidence that healthy students were more likely to give the correct answer. Is it appropriate to conclude that the health of the student affects ability to taste? Why or why not? Explain your reasoning.