Researcher F.H. Messerli published an article titled “Chocolate Consumption, Cognitive Function, and Nobel Laureates” in the October 2012 issue of the New England Journal of Medicine. Th e article shows a positive association between a country’s chocolate consumption and the number of Nobel prizes won by the country (adjusted for population size).
a. Identify the observational units.
b. Identify the explanatory variable and the response variable in this study.
c. Identify a confounding variable that provides an alternative explanation for the higher number of Nobel prizes won by countries with higher chocolate consumption, compared to those with lower chocolate consumption.