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 0.077t – 148 give good
Estimates for the world population in year t?
Explain how you decided.