1. Calculate the sum of the three quizzes:
81 + 76 + 82 = 239
2. Let \( x \) be the score on the fourth quiz.
3. The average of the four quizzes should be at least 80:
\frac{239 + x}{4} \geq 80
4. Multiply both sides by 4 to clear the fraction:
239 + x \geq 320
5. Subtract 239 from both sides to solve for \( x \):
x \geq 81
Therefore, the least you can make on the fourth quiz to have an average of at least 80 is:
\text{Answer} \geq 81