1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mean from two averages

  1. Jan 21, 2008 #1
    1. The problem statement, all variables and given/known data

    The average salary of all female workers is £35,000. The average salary of all male workers is £41,000. What must be true about the average salary of all workers?
    A) It must be £38,000.
    B) It must be larger than the median salary.
    C) It could be any number between £35,000 and £41,000.
    D) It must be larger than £38,000.

    2. Relevant equations

    3. The attempt at a solution

    i think the answe is (C) but i'm not sure
  2. jcsd
  3. Jan 21, 2008 #2
    If there are F female workers and M male workers, then the average salary is (35000F +41000M)/(F+M). If F is fixed and you allow M to vary between 0 and infinity what do you find?
  4. Jan 21, 2008 #3
    oh so if we allow M to vary then (C) is the correct answer...right?
  5. Jan 21, 2008 #4
    Aye indeed.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook