SOLUTION: the marks of 60 students in an sta 122 examination are normally distributed with a mean of 58 and a standard deviation of 18.what are the chances that an individual student, chosen

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Question 437694: the marks of 60 students in an sta 122 examination are normally distributed with a mean of 58 and a standard deviation of 18.what are the chances that an individual student, chosen at random, will have a mark greater than 70?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

*Note: z+=+blue%28x+-+mu%29%2Fblue%28sigma%29

mean of 58 and a standard deviation of 18.  P(x >70)

  z = (70-58)/18 = 12/18 = .6667

 P( z > .6667) = 1 - .7475 = .2525