The figure shows the result of a MINITAB regression analysis of the explanatory variable x = sugar and the response variable y = sodium for the breakfast cereal data set discussed in Chapter 2 (the Cereal data file on the text CD).

a. Suppose you had fit a line to the scatterplot by eyeballing. In what sense would the line calculated by MINITAB be better than your line?
b. Now let€™s look at a histogram of the residuals. Explain what the two short bars on the far right of the histogram mean in the context of the problem. Which two brands of cereal do they represent?

c. In general, how reliable would you say amount of sugar is as a predictor of the amount of sodium?

Transcribed Image Text:

350- 300 250 E 200 150 100- 50 10 15 20 Sugar (9) Histogram of the Residuals (response is Sodium (mg)) -150-100 -50 050 100 150 200 Residual