This might be a stupid question but how

[MSSM2008]

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do you calculate percentile, if you have

Mean
Lowest score
Highest score
Standard Deviation
And your score

For example if the mean in an exam is 83, the highest grade is a 98, the lowest a 64, the standard deviation is 6.4 and my score is a 78

How do I calculate what percentile my score falls in, exactly. I know that one standard deviation includes about 65%, 2 about 95% and 3 about 99.7% percent of test takers.

Thank you

 

[odrade1]

do you calculate percentile, if you have

Mean
Lowest score
Highest score
Standard Deviation
And your score

For example if the mean in an exam is 83, the highest grade is a 98, the lowest a 64, the standard deviation is 6.4 and my score is a 95

How do I calculate what percentile my score falls in, exactly. I know that one standard deviation includes about 65%, 2 about 95% and 3 about 99.7% percent of test takers.

Thank you

If the scores are normally distributed you can calculate the z-score transformation for your grade, then look up the percentage in a z-distribution (normal distribution) table in the back of a statistics book.

95-83 = 12
12/6.4 = 1.88
for a z-score of 1.88 (1.88 standard deviations above the mean), that score is higher than 96.9% of scores, if the scores were normally distributed.

 

[VincentAdultman]

do you calculate percentile, if you have

Mean
Lowest score
Highest score
Standard Deviation
And your score

For example if the mean in an exam is 83, the highest grade is a 98, the lowest a 64, the standard deviation is 6.4 and my score is a 95

How do I calculate what percentile my score falls in, exactly. I know that one standard deviation includes about 65%, 2 about 95% and 3 about 99.7% percent of test takers.

Thank you

http://psych.rice.edu/online_stat/java/normal.html

Just use the info you provided here, because I'm lazy and don't know the exact formula. You fall in the 97th percentile. Well played son.

By the way, love the subtle "pat me on the back" move you pulled by slipping your score in there. The gunner-ism brings a tear to my eye, really does.

 

[MarzMD]

z= (score-mean)/SD. Then you have to look at a z-table to figure out the percentage.

* I think thats the formula for z

 

[Brainsucker]

You can't calculate it exactly because the distribution isn't normal, or even all that close to normal, because it's bashing up against the 100 limit. (You'll see a much bigger tail on the left side of the mode than the right because of this.) Sometimes you even see bimodal distributions, though that doesn't seem to be all that common. Anyway, just be happy you beat the mean by well over an SD, you crazy gunner.

 

[Law2Doc]

Anyway, just be happy you beat the mean by well over an SD, you crazy gunner.

To the OP: To follow up on Brainsucker's sentence, I don't quite understand why converting one numerical yardstick, from which you can already tell you are well above the mean, is of any importance. You got an A. Why does it matter how many standard deviations above the mean it is? Does your school have some warped system where it matters? 😕

 

[Brainsucker]

Gunner wants to know exactly how many people are ahead of him.

 

[MSSM2008]

the numbers were just an example, but thanks for the positive feedback.

 

[Brainsucker]

Whoops, looks like I misread the data. I can understand why you be worried about things if you're on the lower end. (I'm not sure I buy the "just an example" business.) Anyway, isn't MSSM P/F the first two years or is that just NYU? (I know they're affiliated but not the same. Full-on merger fell through.)

 

[VincentAdultman]

Whoops, looks like I misread the data. I can understand why you be worried about things if you're on the lower end. (I'm not sure I buy the "just an example" business.) Anyway, isn't MSSM P/F the first two years or is that just NYU? (I know they're affiliated but not the same. Full-on merger fell through.)

Mt Sinai why did you edit your post from 95 to 78?

 

[Rafa]

Mt Sinai why did you edit your post from 95 to 78?

Gunner wants to know exactly how many people are ahead of him.

...

 

[Brainsucker]

Holy shizznit. I was duped. These nefarious SDNers.