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Homework Help: Need help with statistics

  1. Aug 12, 2010 #1
    need help with this problem
    x~normal(mean= 12, stdev=2)
    item weight from 8 to 16 ounces
    i have a random sample of 7 items and need to find the probability that 3 of those items fulfill the weight
    each item is independent

    this is what i got at the moment
    z=(16-12)/(2) = 2
    p(z<2)-p(z<-2)
    =.9772-.0228
    =.9544
     
    Last edited: Aug 12, 2010
  2. jcsd
  3. Aug 12, 2010 #2

    rock.freak667

    User Avatar
    Homework Helper

    You need to use the transformation Z=(X-μ)/σ, and then read the range off of your table.

    (σ = std.dev, and μ=mean)
     
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