help I have no idea how to solve word problems

Question

a country population in 1993 was 116 million. in 2002 it was 21 million. estimate the population in 2007 using the exponential growth formula. round your answer to the nearest million

Answer 1

P = P₀*b^t

• P = Population in year t
• P₀ = initial population in 1993 = 116 million
• b = growth or decay factor
• t = years since 1993

 

P = 116*b^t

 

In 2002, P = 21 million and t = 2002-1993=9 years:

 

21 = 116*b⁹

21/116 = b⁹

(21/116)^1/9 = b

0.83 ≈ b    (I rounded to 2 decimal places)

 

P = 116*(0.83)^t

 

To estimate the population in 2007, set t = 2007-1993 = 14 and solve for P (use your calculator).