Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Statistics help

  1. Nov 10, 2004 #1

    This is not a physics question. However, I was hoping someone could help me.

    A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2 seconds.
    question: what percentage of customers are still being kept waiting too long?


  2. jcsd
  3. Nov 10, 2004 #2
    1 SD to the right of the mean is 30 s. I think you need to work out P(Z < 30) and take that away from 1, though I can't remember how to do that.
  4. Nov 10, 2004 #3
    about 68% of the area of the normal distribution lies between minus 1 sd and plus sd from the mean. So I think you can find the answer from there by yourself...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook