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Emergency, Help With Stats Please

  1. Feb 17, 2009 #1
    I have a problem which I can't figure out how to do. Can you please explain how to do it.

    1) Six 6 trees are randomly selected from an orange grove. Assume the median yield in the entire grove is 2.8 boxes per tree. What is the probability that the yields from 4 of the 6 trees will exceed 2.8 boxes?

    Which type of distribution would i use to solve this question?
     
  2. jcsd
  3. Feb 17, 2009 #2

    CRGreathouse

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    It doesn't matter what the distribution is (assuming the number of trees is large and there aren't a lot of trees tied at 2.8). Just assume that half are above and half below and use the binomial formula.
     
  4. Feb 17, 2009 #3
    X ~ Bin (n,p)

    n=6, but what does p equal to?
     
  5. Feb 18, 2009 #4

    CRGreathouse

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    What's the chance something is above the median?
     
  6. Feb 18, 2009 #5
    I am guessing 50%?

    Also I have another quick question

    1. Highway paving material is a mix of asphalt, sand, gypsum, and other ingredients.
    Several Abatches@ of paving material are mixed each day. Asphalt content differs from batch to
    batch, with a normal distribution that has mean μ=100 lb per ton and standard deviation σ=6 lb
    per ton.

    a. (15 pts) Sketch a histogram that might represent a sample of 200 batches.

    How would I draw a historgram for this? I mean, how would I figure out how many bars I need and what should the width of it be. If he just told me to draw the curve, I would be able to draw it, but how do i draw the histogram. I know the histogram to have a shape of the normal curve, but how many bars and whats the width?

    What does it mean by 200 batches?
     
  7. Feb 18, 2009 #6

    HallsofIvy

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    Why are you guessing? What is the definition of "median"?
     
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