Results 1 to 4 of 4
Like Tree1Thanks
  • 1 Post By HallsofIvy

Math Help - Calculating average combined speed of unequal ratios

  1. #1
    Newbie
    Joined
    Jul 2012
    From
    USA
    Posts
    2

    Calculating average combined speed of unequal ratios

    Hope someone can help with this.

    Department 'A' answered 1,502 phone calls at an average answer speed of 0.01 seconds.
    Department 'B' answered 890 phone calls at an average answer speed of 8.20 seconds.
    The total calls answered was 2392. Department 'A' answered 62.8% of the calls and Department 'B' answered 37.2%.
    What is the combined average answer speed of both Departments 'A' and 'B?'

    I know that if Departments 'A' and 'B' each answered an equal number of calls, the formula would be:

    8.20 + 0.01
    ----------- = 4.11 seconds
    2

    but it's not a 50/50 ratio. What formula would I use to account for the 63/37 split?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,551
    Thanks
    783

    Re: Calculating average combined speed of unequal ratios

    Quote Originally Posted by StJames View Post
    Department 'A' answered 1,502 phone calls at an average answer speed of 0.01 seconds.
    Speed is not measured in seconds. You probably mean seconds per call. Find the total number of seconds and divide it by the total number of calls. The formula can be simplified when you know the percentages of calls made by the two departments, but this is the next step.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Apr 2005
    Posts
    16,048
    Thanks
    1684

    Re: Calculating average combined speed of unequal ratios

    You are right that you cannot "average" things that way.
    Department A answered 1502 calls in an average time of 0.01 seconds.
    So department A answered 1502 calls in a total time of (1502)(.01)= 15.02 seconds

    Department B answered 890 calls in an average time of 8.20 seconds.
    So department B answered 890 calls in an total time of (890)(8.20)= 7298.

    Over all then the two departments answered 1502+ 890= 2392 calls in 15.02+ 7298= 7313.02 seconds
    So what is average time per call?

    You could also do a "weighted" average .628(0.01)+ .372(8.20).
    (Those won't give exactly the same answer because of round off in calculating the percentages.)
    Thanks from StJames
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Jul 2012
    From
    USA
    Posts
    2

    Re: Calculating average combined speed of unequal ratios

    Many, many thanks!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculating Ratios Problem
    Posted in the Algebra Forum
    Replies: 3
    Last Post: May 25th 2012, 02:20 PM
  2. calculating trig. ratios w/ out a calculator
    Posted in the Trigonometry Forum
    Replies: 8
    Last Post: April 12th 2011, 06:35 PM
  3. average speed
    Posted in the Pre-Calculus Forum
    Replies: 14
    Last Post: November 29th 2010, 06:57 AM
  4. Replies: 2
    Last Post: March 13th 2010, 04:49 AM
  5. average speed.
    Posted in the Math Topics Forum
    Replies: 4
    Last Post: September 18th 2007, 12:01 PM

Search Tags


/mathhelpforum @mathhelpforum