Results 1 to 5 of 5

Thread: Find the Year

  1. #1
    Newbie
    Joined
    Apr 2010
    From
    NJ
    Posts
    13

    Find the Year

    According to data from the U.S. Census Bureau, the population P of Cleveland, Ohio (in thousands) in year x can be approximated by the equation P = .08x^2 - 13.08x + 927 , where x = 0 corresponds to the year 1950. In what year (in the past) was the population about 804, 200?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Anonymous1's Avatar
    Joined
    Nov 2009
    From
    Big Red, NY
    Posts
    517
    Thanks
    1
    Quote Originally Posted by emfn96 View Post
    According to data from the U.S. Census Bureau, the population P of Cleveland, Ohio (in thousands) in year x can be approximated by the equation P = .08x^2 - 13.08x + 927 , where x = 0 corresponds to the year 1950. In what year (in the past) was the population about 804, 200?
    Set $\displaystyle .08(x)^2 - 13.08(x) + 927 = 804,200 $

    $\displaystyle \Rightarrow .08(x)^2 - 13.08(x) - 803273 = 0$

    Then use the quadratic formula to find $\displaystyle x,$ the number of years after $\displaystyle 1950$ this event occurred.

    Note that:

    $\displaystyle a=.08$

    $\displaystyle b=-13.08$

    $\displaystyle c=- 803273$

    $\displaystyle \frac{-b +/- \sqrt{b^2 - 4ac}}{2a}$

    Now plug and chug, as they say.
    Last edited by Anonymous1; Apr 5th 2010 at 08:01 PM.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2010
    From
    NJ
    Posts
    13

    Quadratic Formula

    Quote Originally Posted by Anonymous1 View Post
    Set $\displaystyle .08(x)^2 - 13.08(x) + 927 = 804,200 $

    $\displaystyle \Rightarrow .08(x)^2 - 13.08(x) - 803273 = 0$

    Then use the quadratic formula to find $\displaystyle x,$ the number of years after $\displaystyle 1950$ this event occurred.

    Note that:

    $\displaystyle a=.08$

    $\displaystyle b=-13.08$

    $\displaystyle c=- 803273$

    $\displaystyle \frac{-b +/- \sqrt{b^2 - 4ac}}{2a}$

    Now plug and chug, as they say.
    I had no clue that the quadratic formula was needed to find the answer.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor

    Joined
    Apr 2005
    Posts
    19,725
    Thanks
    3008
    It's not "required" but you did recognise that this is a quadratic equation, didn't you?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    baz
    baz is offline
    Junior Member
    Joined
    Apr 2010
    Posts
    34
    it is straight forward quadractic equation.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: Feb 3rd 2013, 06:48 AM
  2. Replies: 3
    Last Post: Nov 12th 2011, 10:57 AM
  3. Replies: 1
    Last Post: May 19th 2010, 03:37 AM
  4. Find the Year(s)
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: Jan 24th 2010, 08:57 PM
  5. Find the Year(s) #2
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: Jan 24th 2010, 08:56 PM

Search Tags


/mathhelpforum @mathhelpforum