Population Growth: Logarithms

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  • Опубліковано 8 лют 2016
  • This MATHguide video demonstrates how to calculate for population or time within population growth word problems. It also shows how to use logarithms to solve for time. Visit our text based lesson at www.mathguide.com/lessons2/Log....

КОМЕНТАРІ • 98

  • @MATHguide
    @MATHguide  5 років тому +2

    Population Growth Quizmaster
    www.mathguide.com/cgi-bin/quizmasters2/L2.cgi
    Exponential Functions
    www.mathguide.com/lessons3/ExpFunctions.html
    Logarithmic Functions
    www.mathguide.com/lessons2/Logs.html

  • @amyb.6582
    @amyb.6582 3 роки тому +3

    Wow....you broke it down so easy. Thank you!! I have been struggling to grasp this concept.

  • @JesusGutierrez-dm5qt
    @JesusGutierrez-dm5qt 2 роки тому +1

    I was taking an online exam. I could not find any formula in the book for the chapters we studied and spun my wheels for hours. I then found this link. It was exactly what I needed, the variables and explanation were perfect. This question was 33% of the exam score and got it correct. Thank you so much!!!

  • @elf-san
    @elf-san 4 роки тому +10

    I was looking for this one. Thank God you saved my life!

  • @luizarthuraquino5745
    @luizarthuraquino5745 4 роки тому +1

    The logistic population growth model is described by an equation of the form P(t) = PL/(1 − ce−kt) , Where PL, c, and k > 0 are constants, and P(t) is the population at time t. PL represents the limiting value of the population since limt→∞ P(t) = PL. Use the census data for the years 1950, 1960, and 1970 listed in the table on page 105 to determine the constants PL, c, and k for a logistic growth model. Use the logistic model to predict the population of the United States in 1980 and in 2010, assuming t = 0 at 1950. Compare the 1980 prediction to the actual value. *Please Solve ?*

  • @tiagermany8732
    @tiagermany8732 8 років тому +3

    I am so happy I stumbled across your video! Omg 😩...you have helped me out a lot 👌🏽. #NewSubscriber

    • @MATHguide
      @MATHguide  8 років тому +2

      +Tia Germany I'm glad this math resource helped you. There are many more free and interactive resources available at www.mathguide.com/.

  • @tomhall7633
    @tomhall7633 7 років тому +1

    it's not so scary the way you put it, BUT I'M STILL SACRED!

    • @MATHguide
      @MATHguide  7 років тому

      Tom Hall Glad it helped.

  • @nicholas3708
    @nicholas3708 Рік тому +1

    I've found different methods of population projections (arithmetic, geometric and logarithmic). Which method is best and for which scenarios?

  • @kybieee
    @kybieee 2 роки тому +1

    This video is really helpful, thank you!

  • @AlexJamesGTV
    @AlexJamesGTV 6 років тому +1

    perfect thank you!

  • @dinamichellegenuino3318
    @dinamichellegenuino3318 3 роки тому +1

    I learned a lot! Thanks for this

    • @MATHguide
      @MATHguide  3 роки тому +2

      You are very welcome!

    • @dinamichellegenuino3318
      @dinamichellegenuino3318 3 роки тому +1

      @@MATHguide I hope you will also solve about finding the nth term in the Fibonacci sequence.

  • @marcjoshualatonero934
    @marcjoshualatonero934 3 роки тому +1

    Thank you Sir, I've learned a lot😁❤👌👍

  • @shahidullahalkafianik52
    @shahidullahalkafianik52 7 років тому +5

    it's a great one.

    • @MATHguide
      @MATHguide  7 років тому

      Thank you for the support.

  • @mr.jakirhosenronnyronny4705
    @mr.jakirhosenronnyronny4705 5 років тому +1

    Thanks a lot

  • @BigKfishing
    @BigKfishing 5 років тому +4

    you saved my life thank you god bless

  • @elliottmaccrone328
    @elliottmaccrone328 Рік тому +1

    thank you

  • @wtwwhatthewhat
    @wtwwhatthewhat 3 роки тому

    Can you help calculating Noah time starting with 4 couples for 4000 years. Looking at your math model human race started only several thousands years back

  • @Unknown-wv1vl
    @Unknown-wv1vl 3 роки тому +1

    Thank for this

  • @cdt.pequinoja.7392
    @cdt.pequinoja.7392 Рік тому

    Is the pemdas useful in solving this problem?

  • @emmagreat3238
    @emmagreat3238 Рік тому +1

    What of for arithmetic method

  • @lovejoymonton369
    @lovejoymonton369 6 років тому

    how about if your trying to find out how many years it would tak for the population to reach a certain amount?

    • @MATHguide
      @MATHguide  5 років тому

      Check out this lesson. There is a section on human population.
      www.mathguide.com/lessons2/Logs.html

  • @Muqdishomuuqbilan143
    @Muqdishomuuqbilan143 5 років тому

    What is the name of this function??thanks for your explanation.

    • @MATHguide
      @MATHguide  5 років тому

      Logarithms are used to solve exponential equations that have variable exponents.

  • @djjj4277
    @djjj4277 3 роки тому +2

    Life saving you saved me from failing grades thank youuu

  • @tonystark1073
    @tonystark1073 7 років тому

    thanks for the help :)

  • @ruthanns.6259
    @ruthanns.6259 4 роки тому +1

    hiw did you get the 8886
    ...where in the calculator

    • @MATHguide
      @MATHguide  4 роки тому

      A TI-Nspire was used... exactly as you see it here.

  • @dakloos316
    @dakloos316 5 років тому

    Where do you get the constant from? What makes it 2.7182818284?

    • @MATHguide
      @MATHguide  5 років тому

      The constant e comes from a limit. If you calculate (1 + 1/n)^n as n approaches infinity, you will get e.

  • @cessarana3006
    @cessarana3006 2 роки тому +1

    omg, thanks. Now I get it ❤

  • @lilyreallydefgal
    @lilyreallydefgal 3 роки тому +1

    Thank you

  • @joanataglucop5129
    @joanataglucop5129 3 роки тому +1

    I was confused how did you solve it on your calculator. Can you please show it how?

    • @lizzylopez9806
      @lizzylopez9806 3 роки тому

      ugh same

    • @kimberliecrouse9731
      @kimberliecrouse9731 3 роки тому

      plug in ln(400/321) first and it should equal .2202.... then you ans/.007 to equal 31.43

  • @johnroquesidaya5172
    @johnroquesidaya5172 2 місяці тому

    how do you get
    A= 8886?

  • @alien6295
    @alien6295 Рік тому

    Sir
    I need calcilations to find r for t =10
    Please post one video showing the calculation of r for a decade..
    and applying the same r calculation for population projection for next 10 years

    • @MATHguide
      @MATHguide  Рік тому

      You need to watch the video again.

  • @user-jv3mm6vt6e
    @user-jv3mm6vt6e 5 років тому +1

    Спасибо

  • @viljalmr9665
    @viljalmr9665 Рік тому

    I try using calculator is not the same as your answer. can you help me?

  • @johncarlolabrador7161
    @johncarlolabrador7161 3 роки тому +1

    How did it become 31.4?? May calculator says its 3.14? I'll wait for your reply thanks😊

    • @kimberliecrouse9731
      @kimberliecrouse9731 3 роки тому

      plug in ln(400/321) first and it should equal .2202.... then you ans/.007 to equal 31.43

  • @gabba2891
    @gabba2891 4 роки тому

    What if the t is missing and P, A, and r i only in the given?

    • @MATHguide
      @MATHguide  4 роки тому

      You didn't watch the entire video. The second problem answers your question. (See video at 6:29.)
      ua-cam.com/video/ZgOYp0L1BI4/v-deo.htmlm29s

    • @niconico9702
      @niconico9702 3 роки тому

      @@MATHguide is it important that I use "In" instead of "log,"??

  • @marlonarensol1423
    @marlonarensol1423 2 роки тому

    Sir how to get rate

  • @darleneaquino4677
    @darleneaquino4677 3 роки тому +2

    Howd you get 8886? I'm confuse

  • @esmaelayunan4789
    @esmaelayunan4789 3 роки тому

    how get the 8886 can you explain?

    • @MATHguide
      @MATHguide  3 роки тому

      Plug the numbers into the formula.

  • @dragonfairy7822
    @dragonfairy7822 4 роки тому

    Something isn't coming out right for me. 400/321=1.246 Natural log of 2.71 is .9969 | .9969* 1.246 = 1.242 | 1.242/.007 = 177.47 What did I miss?

    • @MATHguide
      @MATHguide  4 роки тому

      ln(1.246) is what you should be doing, not ln(2.71).

    • @dragonfairy7822
      @dragonfairy7822 4 роки тому

      @@MATHguide isn't e = 2.7? and you said the natural log of e was essentially 1 or I calculated it to.9969. I think I am still missing something.

    • @MATHguide
      @MATHguide  4 роки тому +1

      ln(400/321) = ln(1.246) = 0.220, not 0.9969.

  • @jamillavega747
    @jamillavega747 4 роки тому

    Can you show us a problem if P is the missing one?,😥

    • @MATHguide
      @MATHguide  4 роки тому

      It would be A divided by e^(rt).

  • @jasreellou9817
    @jasreellou9817 4 роки тому +1

    I'm confused on how you got 8886 as the answer

    • @MATHguide
      @MATHguide  4 роки тому

      Start watching again at 4:00, or click here.
      ua-cam.com/video/ZgOYp0L1BI4/v-deo.htmlm

  • @rwhelanable
    @rwhelanable 3 роки тому +1

    Geez Louise!

  • @tiktokcompilation8266
    @tiktokcompilation8266 3 роки тому

    Watching this today (October26,2020)

  • @corderoandreafaiths.3525
    @corderoandreafaiths.3525 5 років тому

    31.4? Are u supposed to move the decimal? Or an error?

    • @MATHguide
      @MATHguide  5 років тому

      Check out the calculation, here:
      ua-cam.com/video/ZgOYp0L1BI4/v-deo.htmlm32s

  • @VNZ.00
    @VNZ.00 5 років тому +1

    What if the "r" is missing

    • @MATHguide
      @MATHguide  5 років тому

      Vince Gabad That is a problem similar to the example we have 7 minute into the video. It will involve logarithms.

    • @VNZ.00
      @VNZ.00 5 років тому +1

      MATHguide i actually figure it out from trial and error base on the question 2 so thanks a lot.

    • @MATHguide
      @MATHguide  5 років тому

      Trial and error is a great strategy!

    • @kylea7371
      @kylea7371 5 років тому

      What if P is missing?

    • @robertgenova7206
      @robertgenova7206 5 років тому +1

      @@kylea7371 try this formula
      P= A over e ↑rt

  • @jymii.8738
    @jymii.8738 3 роки тому +2

    Lisoda ani ngart uy

  • @mentor6059
    @mentor6059 4 роки тому +1

    7% is 0.007?????

    • @MATHguide
      @MATHguide  4 роки тому +2

      7% is 0.07. However, the problem has a 0.7%, which is 0.007.
      ua-cam.com/video/ZgOYp0L1BI4/v-deo.html

    • @chinmay2297
      @chinmay2297 3 роки тому +1

      0.7%=7/10%=7/10×1/100=7/1000=0.007

  • @paulna5526
    @paulna5526 5 років тому

    misleading when stating countries have negative growth, people don't understand that the rate may be negative, but the countries are still having growth of population. in other words the population itself is still increasing whether the rate is negative or not. The truth is, that the population will continue to grow, and eventually we will run out of resources, water, food, etc.. when I was born less than 3 billion people on earth, now 7 billion, we will never see a decline in the actual population, only a decline in the rate of growth, and that's why I get angry with statisticians that don't really explain in laymen's terms, that their rhetoric is bs. The worlds population will never go down, it would take a nuclear war or distaster for that to happen, that's why our wonderful governments will have to lead us in that direction at some time in the future, this is a fact, and the only way to avoid this is to colonize into space, in other words, become completely self=sufficient.

    • @MATHguide
      @MATHguide  5 років тому

      Paul N/A You have a lot of thoughts on this. Thank you for sharing.

  • @jackierobles5540
    @jackierobles5540 3 роки тому

    If it's 7 percent for the second problem, it should be 0.07, not 0.007.

  • @rodaneabapo4498
    @rodaneabapo4498 3 роки тому

    hi

  • @nadinerosedestura9696
    @nadinerosedestura9696 3 роки тому +1

    Online class brought me here 😭

  • @bbgr9239
    @bbgr9239 2 роки тому +1

    Jesus Christ loves you 🥺

  • @Skyview585
    @Skyview585 3 роки тому

    I hate math

    • @MATHguide
      @MATHguide  3 роки тому

      Mathematics is the language of the Universe.

  • @luizarthuraquino5745
    @luizarthuraquino5745 4 роки тому

    The logistic population growth model is described by an equation of the form P(t) = PL/(1 − ce−kt) , Where PL, c, and k > 0 are constants, and P(t) is the population at time t. PL represents the limiting value of the population since limt→∞ P(t) = PL. Use the census data for the years 1950, 1960, and 1970 listed in the table on page 105 to determine the constants PL, c, and k for a logistic growth model. Use the logistic model to predict the population of the United States in 1980 and in 2010, assuming t = 0 at 1950. Compare the 1980 prediction to the actual value. *Please Solve ?*

    • @MATHguide
      @MATHguide  4 роки тому

      This isn't a homework help site. Sorry.