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Physics class had a mean = 60 and standard deviation = 6.9History class had a mean = 70 and standard deviation =10.7Simon had the same test score on both tests a day had the same z-score on each test.What was Simon's test score?(round to the nearest whole number)

User MaxiGui
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1 Answer

21 votes
21 votes

Physics class had a mean = 60 and standard deviation = 6.9



History class had a mean = 70 and standard deviation =10.7



Simon had the same test score on both tests a day had the same z-score on each test.



What was Simon's test score?

we know that

The z-score is equal to

z=(x-mean)/s

where

x is the test score

s is the standard deviation

substitute the given values

Physics class

z=(x-60)/6.9

History class

z=(x-70)/10.7

equate both equations

(x-60)/6.9=(x-70)/10.7

solve for x

10.7(x-60)=6.9(x-70)

10.7x-642=6.9x-483

10.7x-6.9x=642-483

3.8x=159

x=41.84

therefore

the test score is 41.84

User Renato Coutinho
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2.5k points
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