Question 821439
A student score on the first 3 class was 65,78 & 84.what range of the score on the forth test will give the student an average that is less than 80 but not less than 70 on the forth test. 
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Equation:
70 < (65+78+84+x)/4 < 80
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280 < 227+x < 320
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Ans:: 53 < x < 93
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Cheers,
Stan H.
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