Sodium and systolic blood pressure. Data from 10 individuals in renal failure with high blood pressure are shown in the following table. The variable SODIUM represents salt consumption (in milligrams) and the variable BP represents systolic blood pressure (in mmHg).

(a) Demonstrate the relationship between sodium intake and systolic blood pressure with a scatterplot. Describe the observed relationship (form, direction, outliers, and strength of the relationship using r as a guide).

(b) Can the observed relationship be easily explained by “chance”?
Justify your response with a single statistic.

(c) Determine the least squares regression line for the data. What does the slope coefficient tell you about the relationship between SODIUM and BP.

(d) What is the predicted BP for a person from this population that consumes 7.0 mg of sodium per day?

(e) What is the value of the residual associated with the first observation? The observed value for the first observation is (7.0, 156).

(f) Draw the regression line on the scatter plot you produced in part

(a) of this exercise. Then, show the residual associated with the first data point on this graph.