Relative growth rate is ,
is a constant.
Initial relative growth rate is , where
is initial value of
,
is change in
and
is change in
.
Initial growth rate is .
Initial growth rate is millions.
.
.
The initial population is .
Substitute ,
and
in
.
.
Relative growth rate is .
The logistic differential equation is , where
is a carrying capacity.
Substitute and
.
,
is in billions.
The logistic differential equation is ,
is in billions.
(b) Use the logistic model to estimate the world population in the year 2000 and compare with the actual population of 6.1
\billion.
\The logistic model equation is , where
.
Substitute and
in
.
.
Substitute ,
,
and
in
.
The logistic model equation is .
The population in year ,
.
Substitute in
.
.
The population in year is
.
(c) Use the logistic model to predict the world population in the years 2100 and 2500.
\The logistic model equation is .
The population in year ,
.
Substitute in
.
.
The population in year is
.
The population in year ,
.
Substitute in
.
.
The population in year is
.
(d) What are your predictions if the carrying capacity is 50 billion.
\The carrying capacity is .
The logistic model equation is , where
.
Substitute and
in
.
.
Substitute ,
,
and
in
.
The logistic model equation is .
The population in year ,
.
Substitute in
.
.
The population in year is
.
The population in year ,
.
Substitute in
.
.
The population in year is
.
The population in year ,
.
Substitute in
.
.
The population in year is
.
(a) The logistic differential equation is ,
is in billions.
(b) The population in year is
.
(c)
\The population in year is
.
The population in year is
.
(d)
\The population in year is
.
The population in year is
.
The population in year is
.