Answer:
[tex]99[/tex]
Step-by-step explanation:
The average of an [tex]x[/tex] amount of values is equal to the sum of all the values divided by [tex]x[/tex]. Thus, for any five scores to have an average score of 85, the sum of the scores must be [tex]85\cdot 5=425[/tex]
Therefore, we have the following equation:
[tex]73+84+91+78+m=425,\\m=\boxed{99}[/tex]
