In 2012, the population of a city was 5.69 million. The exponential growth rate was 2.87% per year. a) Find the exponential growth function. b) Estimate the population of the city in 2018. c) When will the population of the city be 8 million? d) Find the doubling time. a) The exponential growth function is P(t) nothing, where t is in terms of the number of years since 2012 and P(t) is the population in millions. (Type exponential notation with positive exponents. Do not simplify. Use integers or decimals for any numbers in the equation.)

a) The exponential growth function

P(t) = 5,690,000(1.0287)^t

b) 6,742,868.7374 million

c) 12.04 years

d) 2439.0243902

Step-by-step explanation:

In 2012, the population of a city was 5.69 million. The exponential growth rate was 2.87% per year.

The formula for exponential growth is given as:

P(t) = Po( 1 + r) ^t

Where P = Population size after time t

Po = Initial population size

r = Growth rate in percentage

t= time in years

a) Find the exponential growth function.

P(t) = Population size after time t

Po = Initial population size = 5.69 million

r = Growth rate in percentage = 2.87% = 0.0287

t= time in years

The Exponential growth function

P(t) = 5,690,000(1 + 0.0287)^t

P(t) = 5,690,000(1.0287)^t

b) Estimate the population of the city in 2018.

From 2012 to 2018 = 6 years

t = 6 years

Hence,

P(t) = Po( 1 + r) ^t

P(t) = 5,690,000(1 + 0.0287)^6

P(t) = 5,690,000(1.0287)^6

P(t) = 6,742,868.7374 million

c) When will the population of the city be 8 million?

P(t) = 8,000,000

P(t) = Po( 1 + r) ^t

P(t) = 5,690,000(1 + 0.0287)^t

8,000,000 = 5,690,000(1 + 0.0287)^t

8,000,000 = 5,690,000(1.0287)^t

Divide both sides by 5,690,000

8,000,00/5,690,000 = 5,690,000(1.0287)^t/5,690,000

= 1.4059753954 = 1.0287^t

Take logarithm of both sides

log 1.4059753954 = log 1.0287^t

Log 1.4059753954 =t Log 1.0287

t = Log 1.4059753954/Log 1.0287

t = 12.041740264

t = 12.04 years

d) Find the doubling time.

The formula is given as 70/Growth rate

= 70/0.0287

= 2439.0243902