Architectural Designers is creating a schematic for a bridge over the Columbia River whose arch is in the shape of a parabola. The road, 40 feet above the river surface, represents the directrix of the parabolic arch. The focus of the parabolic arch is located 20 feet above the river surface. In the schematic, the river surface will be positioned along the x-axis and the axis of symmetry for the downward opening parabolic arch will be positioned along the y-axis. Which equation best models the parabolic arch in the schematic?

If your score on your next statistics test is converted to a z score, which of these z scores would you prefer: minus2.00, minus1.00, 0, 1.00, 2.00? why? a. the z score of 2.00 is most preferable because it is 2.00 standard deviations above the mean and would correspond to the highest of the five different possible test scores. b. the z score of 0 is most preferable because it corresponds to a test score equal to the mean. c. the z score of minus2.00 is most preferable because it is 2.00 standard deviations below the mean and would correspond to the highest of the five different possible test scores. d. the z score of minus1.00 is most preferable because it is 1.00 standard deviation below the mean and would correspond to an above average