The paper "A Cross-National Relationship Between Sugar Consumption and Major Depression?" (Depression and Anxiety [2002]: 118-120) concluded that there was a correlation between re?ned sugar consumption (calories per person per day) and annual rate of major depression (cases per 100 people) based on data
a. Construct a scatterplot, and comment on the features of the plot.
b. Does there appear to be a linear relationship between the two variables? How would you characterize the relationship?
c. Compute the value of the correlation coef?cient. Is the value of r consistent with your answer to Part (b)?
d. Is it reasonable to conclude that test anxiety caused poor exam performance? Explain.