Q. A town has a population of 9000 and grows at 5% every year. To the nearest year, how long will it be until the population will reach 18900 ?Answer:
Determine growth type: Determine the type of growth. The town's population grows by a fixed percentage each year. This indicates exponential growth.
Identify key values: Identify the initial population P0, the growth rate r, and the final population P.P0=9000r=5% or 0.05 (as a decimal)P=18900
Use exponential growth formula: Use the formula for exponential growth: P=P0×(1+r)t, where P is the final population, P0 is the initial population, r is the growth rate, and t is the time in years.We need to solve for t.
Rearrange formula for t: Rearrange the formula to solve for t.t=log(1+r)log(P0P)Substitute the known values into the equation.t=log(1+0.05)log(900018900)
Substitute values into equation: Calculate the values.t=log(1.05)log(900018900)t=log(1.05)log(2.1)
Calculate values: Use a calculator to find the values of log(2.1) and log(1.05). t≈log(1.05)log(2.1) t≈0.02120.3222 t≈15.1981
Use calculator for logs: Round the result to the nearest year.t≈15 years
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