A professor of statistics at NCSU refutes the claim that the average student spends 3 hours studying for the midterm exam. Which hypothesis is used to test the claim? A. H_0: μ < = 3 vs. H_1: μ > 3
B. H_0: μ = 3 vs. H_1: μ ≠ 3
C. H_0: μ ≠ 3 vs. H_1: μ = 3
D. H_0: μ > = 3 vs. H_1: μ < 3

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)