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2.5.1: Preparation M.5

  • Page ID
    148561
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    (1) Population Growth and Investment Growth:

    (a) The population of a small town was 5,500 people in the year 2010 and census data showed that the population grew by approximately 2.5% every year until 2020. What was the approximate population in 2011? 2012? 2013? 2020? Round to the nearest person.

    Year Population
    2011  
    2012  
    2013  
    2020  

    (b) If Karl invested $5,500 in 2010 in an account which earned 2.5% interest every year, how much money would be in the account after one year? Two years? Three years? Ten years? Round to the nearest penny.

    Year Account Balance
    2011  
    2012  
    2013  
    2020  

    (c) What are the similarities and differences between the previous two situations?

    (2) The population of a small town in Ohio was 5,500 people in the year 2010 and census data showed that the population decreased by approximately 2.5% every year until 2020. What was the approximate population in 2011? 2012? 2020? Round to the nearest person.

    Year Population
    2011  
    2012  
    2020  

    (3) The population of a small town in Michigan was also 5,500 people in the year 2010, but it decreased by an average of 150 people a year until 2020. What was the approximate population in 2011? 2012? 2020?

    Year Population
    2011  
    2012  
    2020  

    (4) What is different about the population change from year to year in the small town in Michigan (in Question 3 above) and the population change from year to year in the small town in Ohio (in Question 2 above)?

    (5) Jennifer owns a clothing store. She wants to increase the price of a $15 shirt at her store by 60%. She performs the calculation two ways: 15 + .6 (15) and 15 (1.6). She gets the same result with each calculation. Explain why both methods work.

    (6) Jennifer has been selling a coat at her store for $125. She decides to have a “30% off everything in the store” sale. Using Question 5 above as a guide, write two math expressions which a customer could use to calculate the sale price of a coat.

    After Preparation M.5 (survey)

    You should be able to do the following things for the next collaboration. Rate how confident you are on a scale of 1–5 (1 = not confident and 5 = very confident).

    Before beginning Collaboration M.5, you should understand the concepts and demonstrate the skills listed below:

    Skill or Concept: I can … Rating from 1 to 5
    recognize exponential modeling.  
    evaluate expressions involving exponents.  

    This page titled 2.5.1: Preparation M.5 is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Carnegie Math Pathways (WestEd) via source content that was edited to the style and standards of the LibreTexts platform.