Answer:
81.3
Step-by-step explanation:
To calculate the average you have to add up all the numbers then divide them by total numbers.
In this case,
[tex]\frac{86.0 + 90.0 + 58.0 + 87.0 + 86.7 + 88.8 + 72.0 +78.3 + 81.0 + 78.3 + 81.7 + 88.0 + 81.0}{13}[/tex]
[tex]\frac{1056.3}{13}[/tex]
[tex]81.2923076 \\Approximately \\ 81.3[/tex]
