At the bowling alley, Alyssa records each bowler’s score and the weight of the bowling ball they used. She limits her study to bowlers with 14-pound balls and 16-pound balls. At the
end of the night she finds that bowlers who used the heavier bowling balls had a higher
average score than bowlers who used the lighter bowling balls.

(a) Explain how you know this is an observational study and not an experiment.

(b) Based on this study, should you conclude that using a heavier ball makes you achieve a
higher score? Explain your reasoning.