SOLUTION: Empirical rule, I am having difficulty working all the steps. If someone could show each step it would be very helpful. At one college GPA's are normally distributed with a mean

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Question 548423: Empirical rule, I am having difficulty working all the steps. If someone could show each step it would be very helpful.
At one college GPA's are normally distributed with a mean of 2.8 and a standard deviation of .5. What percentage of students at the college have a GPA between 2.3 and 3.3?
a)84.13% b)99.74% c) 68.26% d) 95.44%
I choose answer A, but am not sure how I came up with that answer after working problem. I have not been in school in 25 years and have never done this kind of math. Any help you provide would be greatly appriciated.
Wanda Dennis

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
At one college GPA's are normally distributed with a mean of 2.8 and a standard deviation of .5. What percentage of students at the college have a GPA between 2.3 and 3.3?
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How far is 2.3 from 2.8? answer is (2.3-2.8) = -0.5
That means 2.3 is one standard deviation to the left of the mean.
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How far is 3.3 from 2.8? answer is (3.3-2.8) = 0.5
That means 3.3 is one standard deviation to the right of the mean.
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According to the empirical rule 68% of normally distributed
data is within 1 standard deviation of the mean.
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So your answer should be "C".
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Cheers,
Stan H.
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a)84.13% b)99.74% c) 68.26% d) 95.44%