SOLUTION: Please help! This is my last math course and I am so afraid it will ruin my chances of getting my bursury. I am getting high 80's and 90's in my other courses, but math has been

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Question 453909: Please help! This is my last math course and I am so afraid it will ruin my chances of getting my bursury. I am getting high 80's and 90's in my other courses, but math has been such a struggle through high school.
The scholastic aptitude test (SAT) scores are normally distributed with a mean of 500 and a standard deviation of 100.
a) What percentage of students obtain a score between 500 and 600?
b) If you got 725 on this test what would your percentile rank be?
Thanks so much!
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
The scholastic aptitude test (SAT) scores are normally distributed with a mean of 500 and a standard deviation of 100.
a) What percentage of students obtain a score between 500 and 600?
b) If you got 725 on this test what would your percentile rank be?
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z(500) = (500-500)/100 = 0
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z(600) = (600-500)/100 = 100/100 = 1
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P(500< x <600) = P(0< z < 1) = 0.3413
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z(725) = (725-500)/100 = 225/100 = 2.25
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%ile of 725 = P(z < 2.25) = 0.9878 = 99%ile
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Cheers,
Stan H.