1980 was 125,500.the population of the same city in 2000 was 155,00.what year can it be predicted that the city's population will be 200,000?

Question

pls answe this asap!!

Answer 1

30,500 increase in 20 years

that's an annual increase of 3050/2 = 1,525 per year

200,000- 155,000 = 45,000

in 20 years later in 2020, population will be 155,000+ 30,500 = 185,500

another 14,500/1525 = 9.5 more years

in 2030 the population will reach 200,000

if the growth rate is linear

but if it's exponential growth

155.5 = 125e^20r

155.5/125 = e^20r

ln(155.5/125) = 20r

r = ln(155.5/125)/20 = about 1.1% growth rate

200 =125e^.011t

ln200/125 = .011t

t = ln200/125)/.011 = 42.73 years from 1980 = 2023 to reach 200,000

200=155.5e^.011t

ln200/155.5 =.011t

t = (ln200/155.5)/.011 = 22.9 add 22.9 + 2000 = 2023 to reach 200,000

2023 if exponential growth. 2030 if linear growth