Ian Ayres, the author of a popular book titled Super Crunchers, conducted a study to help him decide what to name his book. He placed an ad on google.com, with the ad sometimes giving the title as Super Crunchers and other times giving the title as Th e End of Intuition. Google provided Ayres with data on how oft en a person clicked on the ad to obtain more information, depending on the title given in the ad. It turned out that viewers were significantly more likely to click through on the Super Crunchers ad than on Th e End of Intuition ad, so that’s the title that Ayres chose.
a. Was this an observational study or an experiment? Explain how you know.
b. Identify the explanatory and response variables.

c. Was Ayres justified in concluding that the name Super Crunchers caused a higher click-through rate than the other name? Explain why or why not.