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In a normally distributed set of scores, the mean is 74 and the standard deviation is 1.5. What is the probability that a randomly selected score is between 72.5 and 77? Answer should be written as a percent. Do not round. 

 Mar 19, 2021
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ONE standard deviation below 74   is     74 - 1.5 = 72.5      z -score = .1587

   77 is two standard deviations ABOVE 74      z-score = .9772

 

we want to now the area between these z-scores

   .9772  -  .1587 = .8185              so  81.85%  out of 100% of the scores are between  72.5  and 77

 Mar 19, 2021

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