Answer:469 million
Explanation:
Given
The population of a country at t=1900 is 420 million
and P'(t) is a constant therefore P(t) is a linear function of time
assuming P(t)=7t +c
at t=0 i.e. 1900 at starting Point P(t)=420 million
i.e.
Thus
Thus at 1907 Population is 469 million
P'(t)=7 indicates that growth rate of Population is constant equals to 7 billion