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    can someone explain this to me please
    X = the height of chairs (cm)
    X has a mean of 60 and a standard deviation of 2. A random sample of 400 chairs made is taken.
    Find then mean and SD of X(bar)
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    not sure if you have enough info?
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    (Original post by mad_ad666)
    not sure if you have enough info?
    see thats what i thought i dunno though
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    Are you sure that's all the info given. If yh then surely the mean is 60 and the SD is 2 :s
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    i think you have not enough info. if it gave you a probability you could then look back on your percentage tables to find a z value and then use simultaneous eqs to find x-bar and s.d.
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    (Original post by nushii)
    can someone explain this to me please
    X = the height of chairs (cm)
    X has a mean of 60 and a standard deviation of 2. A random sample of 400 chairs made is taken.
    Find then mean and SD of X(bar)
    H~N(60, 2^2)

    write it out like this.. and you should have more information than the random sample.
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    (Original post by mad_ad666)
    i think you have not enough info. if it gave you a probability you could then look back on your percentage tables to find a z value and then use simultaneous eqs to find x-bar and s.d.
    okay then i'll try that thank yu
 
 
 
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