The percentage of the U.S. population that resides in metropolitan areas increased from about 78% in 1980 to about 83% in 2006.

a) Calculate the percentage of the U.S. population residing in metropolitan areas in 1992.

b) Predict the percentage of the U.S. population residing in metropolitan areas in 2012.

Solution:

       Assuming linear growth:

                                     a)   78   +   (83 - 78)*12/26 = 80.31 %

                                     b)   78   +   (83 - 78)*32/26 = 84.15 %