The following data represent the number of calories per serving and the number of grams of sugar per serving for a random sample of high-protein and moderate protein energy bars.

(a) Draw a scatter diagram of the data, treating calories as the explanatory variable. What type of relation, if any, appears to exist between calories and sugar?
(b) Determine the least-squares regression equation from the sample data.
(c) Compute the standard error of the estimate.
(d) Determine whether the residuals are normally distributed.
(e) Determine sb1.
(f) If the residuals are normally distributed, test whether a linear relation exists between calories and sugar content at the a = 0.01 level of significance.
(g) If the residuals are normally distributed, construct a 95% confidence interval about the slope of the true least-squares regression line.
(h) For a randomly selected energy bar, would you recommend using the least-squares regression line obtained in part (b) to predict the sugar content of the energy bar? Why? What would be a good estimate for the sugar content of the energy bar?

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Calories, x Sugar, y Calories, r Sugar, y 180 10 270 20 200 18 320 2 210 14 110 10 220 20 180 12 220 200 22 230 28 220 24 240 2 230 24