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brittany's first four quiz grades are 78 81 69 and 94 what would her next quiz score need to be in order to have a mean score of 79

User Vergil
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2 Answers

4 votes
she would need to get a 73 on her next quiz. if you add them all up and then divide the total by 5, her mean score is 79.
User Chris Brand
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2 votes
The mean is the sum of all numbers divided by the number of numbers. We can set up an equation:


\sf(78+81+69+94+x)/(5)=79

Where 'x' is the next quiz score she need. Solve for 'x'. Multiply 5 to both sides:


\sf 78+81+69+94+x=395

Add:


\sf 322+x=395

Subtract 322 to both sides:


\boxed{\sf x=73}

So her next quiz score needs to be 73 in order to have a mean score of 79 on all her quizzes.
User FastSolutions
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