Answer:
87
Step-by-step explanation:
We know Heather recieved grades of 80, 75 and 86.
Let's find her average on those 3 tests.
80 + 75 + 86 = 241 Since there are 3 tests we divide by 3.
241/3 = 80.3333 Is her aveerage on the first 3 tests.
She need to average 82 so we can write an equation with t being the score on her 4th test.
[tex]\frac{80 + 75 + 86 + t}{4} = 82[/tex]
[tex]\frac{241 + t}{4} = 82[/tex] Multiply each side by 4
([tex]\frac{241+t}{4}[/tex]) * 4 = 82 * 4 4 on the left will cancel
241 + t = 328 Subtract 241 from each side
241 - 241 + t = 328 - 241
t = 328 - 241
t = 87
Heather must get an 87 to have an average score of 82.
