Important risk factors for high blood pressure reported by the National Institute of Health include weight and ethnicity. High blood pressure is common in adults who are overweight and are African American. a public policy researcher in Atlanta surveyed 150 adult men about 5′10″ in height and in the 55–60 age group. Data were collected on their systolic pressure, weight (in pounds), and race (Black = 1 for African American, 0 otherwise). The resulting regression equation which includes the interaction between weight and race is: Systolic = 70.8312 + 0.4362Weight + 30.2482Black − 0.1118(Weight × Black). The interaction variable is negative and statistically significant at the 5% level. Interpret what a negative interaction implies in this example:

For every corresponding pair of cross sections, the area of the cross section of a sphere with radius r is equal to the area of the cross section of a cylinder with radius and height 2r minus the volume of two cones, each with a radius and height of r. a cross section of the sphere is and a cross section of the cylinder minus the cones, taken parallel to the base of cylinder, is the volume of the cylinder with radius r and height 2r is and the volume of each cone with radius r and height r is 1/3 pie r^3. so the volume of the cylinder minus the two cones is therefore, the volume of the cylinder is 4/3pie r^3 by cavalieri's principle. (fill in options are: r/2- r- 2r- an annulus- a circle -1/3pier^3- 2/3pier^3- 4/3pier^3- 5/3pier^3- 2pier^3- 4pier^3)