Suppose a research team is interested in examining the effects of background noise and lighting on sales in Starbucks coffee shops. The research team conducts an experiment that manipulates different levels of background noise and lighting.

(a) Based on the description above, which experimental design would be more appropriate? A randomized block design or a factorial design? Explain your answer.

(b) Suppose a member of the research team argues that the results of the experiment were affected by a statistical regression effect (or regression-to-the-mean effect). Describe an example of how this could arise in this experimental study on Starbucks.