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In: Statistics and Probability

Sarah scores an 85 on an (IQ) test with a mean of 94 and a standard...

Sarah scores an 85 on an (IQ) test with a mean of 94 and a standard deviation of 10. At what percentile rank is she with respect to the rest of the population?

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Expert Solution

µ =    94              
σ =    10              
left tailed                  
P( X ≤    85.000   )          
                  
Z =(X - µ ) / σ = (   85   -   94   ) /    10
Z =    -0.900              
P(X ≤   85   ) = P(Z ≤   -0.90   ) =   0.1841
excel formula for probability from z score is =NORMSDIST(Z)                  

her percentile is 18.41 th

orchestra answered 1 year ago
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