World population: The table lists actual and projected World population p in billions for selected years t. t 1974 1987 1999 2012 p 4 5 6 7 (a) Find the slope of each line segment connecting Consecutive data points in the table. Can these Data be modeled with a line? Explain. (b) Does the polynomial 0.077 t - 148 give good Estimates for the world population in year t ? Explain how you decided. .