Question 152680: On five exams, Alex has scored 84, 86, 71, 91, and 98 points out of 100. He wants to earn at least a B in the course, which corresponds to an overall average grade of 82 or better. Out of 100 points, what is the minimum number of points Alex must earn on the final exam to achieve this goal?
PLEASE HELP..I'M SO CONFUSING!!!!
Answer by Electrified_Levi(103)   (Show Source):
You can put this solution on YOUR website! Hi, Hope I can help,
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On five exams, Alex has scored 84, 86, 71, 91, and 98 points out of 100. He wants to earn at least a B in the course, which corresponds to an overall average grade of 82 or better. Out of 100 points, what is the minimum number of points Alex must earn on the final exam to achieve this goal?
PLEASE HELP..I'M SO CONFUSING!!!!
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First, we have to know a formula for an average
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The average formula is = 
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We have five numbers, we are trying to find the sixth number
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There are going to be six numbers, now we can replace the unknowns for what we know, (we don't know the sixth number(we will use "x"))( He has to at least get an Average of 82)
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 = 
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We can add the five numbers we know
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= 
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We can know cross multiply to get rid of the fraction
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It will become 
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we will use distribution
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= 
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We can know solve "x", we will move "430" to the right side
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 = 
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He will have to get a 62 on his next exam to get a "B" in the Class
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We can check by replacing "x" with "62" in our original equation
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= 
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 = 
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=  ( True)
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Your answer is "62", He has to at least get a "62" on his last exam
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Hope I helped, Levi
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