Please im desperate! stat/probability

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melyl7105

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Jan 19, 2010
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I am being honest, i havent have math in 9 years, and just do not know how to go about solving this problem. i tried looking and cant find an example that is similar to this. I would appreciate it very much if someone would be kind to explain and show me how to do this.

Mary and peter are twins, very competitive. They are taking statistics. 2 tests, type a taken by mary and type b taken by peter.

type a = 0-100 x bar-average= 50 pts , and S -standard deviation = 20pts

type b =0-100 x bar-average= 50 pts , and S -standard deviation = 30pts

A- mary is better
b- peter is better
C- they are the same.

Thank you so much!
 
The average for both is 50 according to the data (unusual).
Peter can get higher scores than Mary due to his greater variance.
Standard deviation is a variance calculation.
However, he also gets lower scores.
As we don't have any reasons for this variance
(alcoholism, knows some aspects very well compared to others, an illness, sometimes comes late for the tests etc)
there is not enough data to conclude if he is better.
 
so he failed to mention they scored 75pts each and also switched them around- peter A, and mary b..

so it was

type a = 0-100 x bar-average= 50 pts , and S -standard deviation = 20pts 75- 50/20=25/20=1.25

type b =0-100 x bar-average= 50 pts , and S -standard deviation = 30pts 30pts 75-50/30=25/30=.8333
and peter is better but i dont know why to i put mary cause she was closer to the average
 
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