To solve this problem, we need to calculate the average predicted high temperatures for both Kingsport and Destin from Sunday to Thursday. We will then determine the required high temperature for Destin on Thursday such that its average high is 10 degrees warmer than Kingsport's average high.
- Calculate the average high temperature for Kingsport from Sunday to Thursday.
- Calculate the average high temperature for Destin from Sunday to Wednesday.
- Determine the required high temperature for Destin on Thursday to make its average 10 degrees higher than Kingsport's average.
The predicted high temperatures for Kingsport from Sunday to Thursday are \( 68, 72, 73, 75, 72 \). The average high temperature can be calculated as follows:
\[
\text{Average}_{\text{Kingsport}} = \frac{68 + 72 + 73 + 75 + 72}{5} = \frac{360}{5} = 72.0
\]
The predicted high temperatures for Destin from Sunday to Wednesday are \( 84, 82, 78, 80 \). The sum of these temperatures is:
\[
\text{Sum}_{\text{Destin}} = 84 + 82 + 78 + 80 = 324
\]
To find the required high temperature for Destin on Thursday, we need to ensure that the average high temperature for Destin is \( 10 \) degrees warmer than that of Kingsport. Thus, we set up the equation:
\[
\text{Average}_{\text{Destin}} = \frac{\text{Sum}_{\text{Destin}} + \text{Required}_{\text{Thursday}}}{5}
\]
We want:
\[
\text{Average}_{\text{Destin}} = \text{Average}_{\text{Kingsport}} + 10
\]
Substituting the known values:
\[
\frac{324 + \text{Required}_{\text{Thursday}}}{5} = 72.0 + 10
\]
This simplifies to:
\[
\frac{324 + \text{Required}_{\text{Thursday}}}{5} = 82.0
\]
Multiplying both sides by \( 5 \):
\[
324 + \text{Required}_{\text{Thursday}} = 410
\]
Solving for \( \text{Required}_{\text{Thursday}} \):
\[
\text{Required}_{\text{Thursday}} = 410 - 324 = 86.0
\]
The required high temperature for Destin on Thursday is \\(\boxed{86.0}\\).