SOLUTION: Assume that a set of test scores is normally distributed with a mean of 129 and a standard deviation of 5. The percentage of scores between 110 and 125 is ____%.
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-> SOLUTION: Assume that a set of test scores is normally distributed with a mean of 129 and a standard deviation of 5. The percentage of scores between 110 and 125 is ____%.
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Question 1003845: Assume that a set of test scores is normally distributed with a mean of 129 and a standard deviation of 5. The percentage of scores between 110 and 125 is ____%. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! Need z-score
z=(xbar-mean)/sd
want z between (110-129)/5=-19/5=-3.8
and (125-129)/5=-0.8
That is 0.2118 ANSWER
That makes sense because it is essentially the probability of being less than -0.8 sd, and to the left of -1 sd is 0.1584.
