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Homework Help: The difference btwn marginal distribution and conditional distribution ?

  1. Mar 3, 2008 #1
    The difference btwn marginal distribution and conditional distribution ???

    So I have a table that "apparently" shows how a company's employees commute to work.


    TRANSPORTATION
    JOB CLASS CAR BUS TRAIN TOTAL
    MANAGEMENT 26 20 44 90
    LABOR 56 106 168 330
    TOTAL 82 126 212 420​


    As you look at my sorry attempt to re-create the table I was given...
    So now I must find the marginal ditrubution (in %) of mode of transportation as well as the conditional distribution (in%) of mode of tranportation for management.

    When I read the definition of a conditional distribution in lead me to think that in order to find that I would devide the data under management [26,20,44] by the total [90].

    The marginal distribution I am lost on.

    Can someone help me ? Please ?
    Thank you !
     
  2. jcsd
  3. May 25, 2011 #2
    Re: The difference btwn marginal distribution and conditional distribution ???

    I can help you with the marginal distribution.
    You have to find the individual probability of each mode of transportation
    for instance : P(Car)=(82/420)
    P(BUS)=(126/420)
    p(tRAIN)=212/420
    SUM OF PROB EQUAL ONE, SO YOU HAVE A MARGINAL DISTRIBUTION.
    FOR THE CONDITIONNAL ONE i THINK YOU ARE RIGHT, YOUR CONDITION IS WELL MANAGEMENT.
     
  4. May 25, 2011 #3

    Ray Vickson

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    Re: The difference btwn marginal distribution and conditional distribution ???

    You have two marginal distributions: (1) the distribution of transportation mode (i.e., what percentages of ALL employees---both labor and management---take car, bus or train; and (2) the distribution of employee type (i.e., what percentage of employees are labor and what percentage are management).

    RGV
     
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