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Homework Help: Probability UNITS?

  1. Sep 10, 2006 #1
    for example, im doing a question involving the probability of the number of apples i eat in a day.

    i need to find the mean, mode, median, variance and standard deviation.

    do these values need to be in units of apples? or just like a numerical value such as 2.3 ?

  2. jcsd
  3. Sep 10, 2006 #2
    In the standard way of definining it, probability values are unitless. Say you had 2 green apples and 1 red apple. The probability of you picking a red apple is (1 apple)/(3 apples)=1/3. Essentially, the units of "apple" cancel, leaving only a number.

    However, the mean, mode, median, variance, and standard deviation all have units. The first three are essentially ways of averaging, and so must have units of apples. The variance has units of apples^2, and the standard deviation has units of apples.
  4. Sep 10, 2006 #3
    wow i never wuda thought maybe the other things but not variance being apple squared thanks
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