Answer:
Ashley = 79
Step-by-step explanation:
[tex]Average=\frac{Carla+Bev+Ashley}{3}=78\\\\\frac{80+75+Ashley}{3}= 78 \\\\\frac{155+Ashley}{3}=78\\\\\frac{155+Ashley}{3}*\frac{3}{1} =78*3\\\\155+Ashley=234\\[/tex]
Subtract 155 from both sides;
Ashley = 79