Answer:
You would need to score a 10.
The equation is going to have a total of 5 values where one is unknown. We will call this unknown x and include it as a value in the equation.
Since we are going to have to find an average, we will need a fraction. We also know we will take five total tests. This will equal 12 as this is the desired average.
To start, create the fraction that will add all five values together and divide that by the number of values.
[tex]\displaystyle \frac{12+14+11+13+x}{5}[/tex]
Then, set this equal to 12.
[tex]\displaystyle \frac{12+14+11+13+x}{5}=12[/tex]
To solve, we will first combine all like terms.
[tex]\displaystyle \frac{50+x}{5}=12[/tex]
Then, divide the fraction.
[tex]\displaystyle 10+\frac{x}{5}=12[/tex]
Now, move the constants to the right side of the equation. To do this, subtract 10 from 12.
[tex]\displaystyle \frac{x}{5}=2[/tex]
Finally, multiply both sides of the equation by 5 to get rid of the denominator.
[tex]x=10[/tex]
Therefore, on test 5, you must score a 10 to maintain an average of 12.
To learn more about averages, visit this link:
https://brainly.com/question/10771800
