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population growth

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    The population of a town doubles every 12 years. If the population in 1945 was 11,005 people, what w

    The population of a town doubles every 12 years. If the population in 1945 was 11,005 people, what was the population in 1981? Calculate the difference in years: Difference = 1981 - 1945 Difference = 36 Calculate doubling periods: Doubling periods = Total years / Doubling time Doubling periods...
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    A population of 200 doubles in size every hour. What is the rate of growth of the population after 2

    A population of 200 doubles in size every hour. What is the rate of growth of the population after 2.5 hours? Time 1: 400 Time 2: 800 Time 3: 1200 (Since it's only 1/2 of a period)
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    Suppose a city's population is 740,000. If the population grows by 12,620 per year, find the populat

    Suppose a city's population is 740,000. If the population grows by 12,620 per year, find the population of the city in 7 years. We setup the population function P(y) where y is the number of years of population growth, g is the growth per year, and P(0) is the original population. P(y) = P(0) +...
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    The population of Westport was 43,000 at the beginning of 1980 and has steadily decreased by 1% per

    The population of Westport was 43,000 at the beginning of 1980 and has steadily decreased by 1% per year since. Write an expression that shows the population of Westport at the beginning of 1994 and solve. 1994 - 1980 = 14 years. Using our population calculator, we get: 37,356
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    A Petri dish contains 2000. The number of bacteria triples every 6 hours. How many bacteria will exi

    A Petri dish contains 2000. The number of bacteria triples every 6 hours. How many bacteria will exist after 3 days? Determine the amount of tripling periods: There are 24 hours in a day. 24 hours in a day * 3 days = 72 hours 72 hours / 6 hours tripling period = 12 tripling periods Our...
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    A city’s population in the 1987 was 125,524. In 2007 the population was 436,884. Determine the popul

    A city’s population in the 1987 was 125,524. In 2007 the population was 436,884. Determine the population rate of increase or decrease Find the population change: Population Change = New Population - Old Population Population Change = 436,884 - 125,524 Population Change = 311,360 Since the...
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    Suppose a city's population is 740,000. If the population grows by 12,620 per year, find the populat

    Suppose a city's population is 740,000. If the population grows by 12,620 per year, find the population of the city in 7 years Set up the population function P(y) where y is the number of years since now: P(y) = Current population + Growth per year * y Plugging in our numbers at y = 7, we get...
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    A population grows at 6% per year. How many years does it take to triple in size?

    A population grows at 6% per year. How many years does it take to triple in size? With a starting population of P, and triple in size means 3 times the original, we want to know t for: P(1.06)^t = 3P Divide each side by P, and we have: 1.06^t = 3 Typing this equation into our search engine to...
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    A town has a population of 50,000. Its rate increases 8% every 6 months. Find the population after 4

    A town has a population of 50,000. Its rate increases 8% every 6 months. Find the population after 4 years. Every 6 months means twice a year. So we have 4 years * twice a year increase = 8 compounding periods. Our formula for compounding an initial population P at time t is P(t) at a...
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    A social networking site currently has 38,000 active members per month, but that figure is dropping

    A social networking site currently has 38,000 active members per month, but that figure is dropping by 5% with every month that passes. How many active members can the site expect to have in 7 months? Setup an equation S(m) where m is the number of months that pass: S(m) = 38000 * (1 - 0.05)^t...
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    On January 1st a town has 75,000 people and is growing exponentially by 3% every year. How many peop

    On January 1st a town has 75,000 people and is growing exponentially by 3% every year. How many people will live there at the end of 10 years? Using our population growth calculator, we get: 100,794
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    A celebrity 50,000 followers on Instagram. The number of follower increases 45% each year. How many

    A celebrity 50,000 followers on Instagram. The number of follower increases 45% each year. How many followers will they have after 8 years? We set up a growth equation for followers F(y), where y is the number of years passed since now: F(y) = 50000 * (1.45)^y <-- since 45% is 0.45 The...
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    A colony of 995 bacteria doubles in size every 206 minutes. What will the population be 618 minutes

    A colony of 995 bacteria doubles in size every 206 minutes. What will the population be 618 minutes from now? Calculate the doubling time periods: Doubling Time Periods = Total Minutes From Now / Doubling Period in Minutes Doubling Time Periods = 618/206 Doubling Time Periods = 3 Calculate the...
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    In 2010, the population of Greenbow, AL was 1,100 people. The population has risen at at rate of 4%

    In 2010, the population of Greenbow, AL was 1,100 people. The population has risen at at rate of 4% each year since. Let x = the number of years since 2010 and y = the population of Greenbow. What will the population of Greenbow be in 2022? P(x) = 1,100(1.04)^x x = 2022 - 2010 x = 12 years...
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    A town has a population of 25,000 and grows at 7.7% every 4 months. What will be the population afte

    A town has a population of 25,000 and grows at 7.7% every 4 months. What will be the population after 6 years? 1 year = 12 months 12 months / 4 months = 3 compounding periods per year 3 compounding periods per year * 6 years = 18 compounding periods So we have our population growth as...
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    A colony of 100 bacteria doubles in size every 34 hours. What will the population be 68 hours from n

    A colony of 100 bacteria doubles in size every 34 hours. What will the population be 68 hours from now T(0) = 100 T(34) = 100 * 2 = 200 T(68) = 200 * 2 = 400
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    In 2016 the geese population was at 750. the geese population is expected to grow at a rate of 12% e

    In 2016 the geese population was at 750. the geese population is expected to grow at a rate of 12% each year. What is the geese population in 2022? 12% is also 0.12. We have the population growth function: P(t) = 750(1.12)^t 2022 - 2016 is 6 years of growth. We want P(6). P(6) = 750(1.12)^6...
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    A city has a population of 260,000 people. Suppose that each year the population grows by 8.75% . W

    A city has a population of 260,000 people. Suppose that each year the population grows by 8.75% . What will the population be after 12 years? Use the calculator provided and round your answer to the nearest whole number. Using our population growth calculator, we get P = 711,417
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