A skateboard halfpipe is being designed for a competition. The halfpipe will be in the shape of a parabola and will be positioned above the ground such that its focus is 20 ft above the ground. Using the ground as the x-axis, where should the base of the halfpipe be positioned? Which equation best describes the equation of the halfpipe?

Which term best describes the association between variables a and b? no association a negative linear association a positive linear association a nonlinear association a scatterplot with an x axis labeled, variable a from zero to ten in increments of two and the y axis labeled, variable b from zero to one hundred forty in increments of twenty with fifteen points in a positive trend.