1. A researcher believes that there is a linear association between the level of potassium content (y) in milligrams and the amount of fiber (x) in grams in cereal. The regression line for the data is computed to be: = 36+27x rate. It was also computed that r = .62

a. If a cereal has 4 grams of fiber, what is its predicted potassium content?

b. If a cereal has 4 grams of fiber and a potassium content of 160 milligrams, what is the value of the residual?

c. Explain in detail what a residual is and what information it provides about the model and the data point.

2. A recent study showed that the hours a person exercised in a week affected the individual's resting heart rate. It was computed that r = -.68 and the least squares regression line was = 83-1.4x, where x is the hours exercised and y is the resting heart rate.

a. What does the value -.68 tell you about the relationship between hours exercised resting heart rate?

b. What does the value 83 tell you about the relationship between hours exercised resting heart rate?

c. What does the value -1.4 tell you about the relationship between hours exercised resting heart rate?

d. What percentage of variability in resting heart rate can be explained by variability in hours exercised?