Results 1 to 4 of 4

Math Help - [SOLVED] Interest rates!!

  1. #1
    Newbie
    Joined
    Mar 2010
    From
    virginia
    Posts
    5

    [SOLVED] Interest rates!!

    Using the formula

    A= P(1 + r/n) ^tn

    At what interest rate to the nearest hundredth of a percent, will 16,000 grow to 20,000 if invested for 5.25years and the interest is compounded quarterly?

    I have hit a wall with this one! Please help if you can..
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,695
    Thanks
    450
    Quote Originally Posted by momuvfour View Post
    Using the formula

    A= P(1 + r/n) ^tn

    At what interest rate to the nearest hundredth of a percent, will 16,000 grow to 20,000 if invested for 5.25years and the interest is compounded quarterly?

    I have hit a wall with this one! Please help if you can..
    20000 = 16000\left(1+\frac{r}{4}\right)^{(5.25)(4)}<br />

    solve for r
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Mar 2010
    From
    virginia
    Posts
    5

    I'm still stuck here

    I understand the set up and I get about halfway through it but this is where I am stuck..

    20000/16000 = (1+r/4)^21

    1.25 = (1+r/4)^21

    Any ideas from here? Sorry my math editor would not copy over..

    Follow Math Help Forum on Facebook and Google+

  4. #4
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by momuvfour View Post
    I understand the set up and I get about halfway through it but this is where I am stuck..

    20000/16000 = (1+r/4)^21

    1.25 = (1+r/4)^21

    Any ideas from here? Sorry my math editor would not copy over..
    Take the 21st root of both sides:

    1+ \frac{r}{4} = \sqrt[21]{1.25}


    which can be evaluated on a calculator.


    Also, if you want to see what someone has typed in LaTeX click on their working to give the code
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. interest rates.
    Posted in the Business Math Forum
    Replies: 6
    Last Post: February 22nd 2011, 12:47 PM
  2. Compound interest at changing interest rates
    Posted in the Business Math Forum
    Replies: 2
    Last Post: October 21st 2010, 04:55 AM
  3. questions about interest rates
    Posted in the Business Math Forum
    Replies: 1
    Last Post: May 10th 2009, 10:37 AM
  4. interest rates
    Posted in the Math Topics Forum
    Replies: 4
    Last Post: November 6th 2008, 03:37 AM
  5. interest rates
    Posted in the Business Math Forum
    Replies: 8
    Last Post: August 18th 2006, 04:30 AM

Search Tags


/mathhelpforum @mathhelpforum