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Statistics Question - Normal Distribution

  • Thread starter Chewy0087
  • Start date
  • #1
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Statistics Question - Normal Distribution SOLVED

Homework Statement


Hey, the question is shown in the attached document.


Homework Equations


Mean = 79 Standard Deviation = 12


The Attempt at a Solution


I dispise these questions, and i'm failing to grasp them at all.

I've done the first two parts fine, but it's part c i'm struggling on.

I've tried using the z function getting me to;

P (Z [tex]\leq[/tex] [tex]\frac{b}{12}[/tex] ) - P ( Z [tex]\leq[/tex] [tex]\frac{-a}{12}[/tex] ) = 0.375

But i've got no idea what i'm doing :/ this question has totally thrown me, all of the methods i've used replacing the 2nd equation into the first have given me useless answers, I can usually do these questions fine, but i'm struggling here, any help would be great!
 

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Answers and Replies

  • #2
370
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never mind, got it, ridiculously easy AGAIN
 

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