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Homework Help: Statistics - Describing distribution curve? - Easy solve

  1. Dec 9, 2009 #1
    This should be a very easy problem, i just can't seem to find what makes the center, shape and spread.

    The distribution of actual weights of 8-ounce chocolate bars produced by a certain machine is normal with mean 8.1 ounces and standard deviation 0.1 ounces. Company managers do not want the weight of a chocolate bar to fall below 7.85 ounces, for fear that consumers will complain.

    Four candy bars are selected at random and their mean weight, x-bar, is computed.
    Describe the center, shape, and spread of the sampling distribution of x-bar.

    My method:

    Mean of x-bar = Mean
    So, the mean of x-bar = 8.1 ounces

    Standard Deviation of x-bar = (standard deviation)/sqrt(n)
    So, 0.1/sqrt(4) = 0.1/2 = 1/20

    Okay, now the distribution curve for x-bar is going to have the characteristics of mean = 8.1 and standard deviation = 0.05. I've gotten that far, but now i don't know how to describe the center (I'm assuming this is 8.1?), shape, and spread or the distribution curve?

    Any help?
  2. jcsd
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