Question

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

Answer 1

The mean is the sum of all numbers divided by the number of numbers. We can set up an equation:

$\sf\dfrac{78+81+69+94+x}{5}=79$

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.

Answer 2

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.