After its fastest rate of growth ever during the 1980s and 1990s, the rate of growth of world population is expected to slow dramatically in the twenty-first century. The function

G(t) = 1.58e−0.213t
gives the projected annual average percent population growth per decade in the tth decade, with t = 1 corresponding to 2000.†
(a) What will the projected annual average population growth rate be in 2020 (t = 3)? (Round your answer to two decimal places.)


% per decade

(b) How fast will the projected annual average population growth rate be changing in 2020 (t = 3)? (Round your answer to two decimal places.)


% per decade per decade

1 answer

a. G(t0 = 1.58*e^n.

n = -0.213*t = -0.213*3 = -0.639.

G(t) = 1.58*e^-0.639=1.58*0.5278=0.83.
% per decade.

b. 0.83%/dec. * (1/10dee.) =0.08 % per
decade per decade.