Regression between cereal sodium and sugar Let x = sodium and y = sugar for the breakfast cereal data in the Cereal data file on the book’s website and in Table 2.3 in Chapter 2.

a. Construct a scatterplot. Do any points satisfy the two criteria for a point to be potentially influential on the regression? Explain.

b. Find the regression line and correlation, using all the data points, and then using all except a potentially influential observation. Summarize the influence of that point.