In this exercise, we estimate the rate at which the total personal income is rising in the richmond-petersburg, virginia, metropolitan area. in 1999, the population in this area was 961400, and the population was increasing at roughly 9200 people per year. the average annual income was 30593 dollars per capita, and this average was increasing at about 1400 dollars per year [a little above the national average of about 1225 dollars yearly] .
use the product rule and these figures to estimate the rate at which the total personal income was rising in the richmond-petersburg area in 1999.

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)