First score = 70
Second score = 72
Third score = ?
[tex]\begin{gathered} \text{Average = }\frac{First\text{ score + Second score + Third score}}{3}\text{ } \\ \end{gathered}[/tex][tex]\begin{gathered} \text{Average = }\frac{70+72+(Third\text{ score)}}{3} \\ \text{Average = }\frac{142+(Third\text{ score)}}{3} \end{gathered}[/tex][tex]\text{Average }\ge\text{ 75.2}[/tex][tex]\begin{gathered} \frac{142+Third\text{ score}}{3}\ge75.2 \\ 142\text{ + Third score }\ge\text{ 3(75.2)} \\ 142\text{ + Third score }\ge\text{ }225.6 \\ \text{Third score }\ge\text{ 225.6 - 142} \\ \text{Third score }\ge\text{ }83.6 \end{gathered}[/tex]