Answer: [tex]W(t)=-3t+6.8[/tex]
Step-by-step explanation:
1. The form of a linear function is:
[tex]y=mx+b[/tex]
Where m is the slope and b is the y-intercept.
2. You know that the water level decreases at a rate of 3 in/day, this means that the slope of the function is -3.
3. The average water level in a retention pond is 6.8 feet, this means that the maximum level of the water is 6.8 feet, because the function decreases while x increases.
4. Then, the linear function is:
[tex]W(t)=-3t+6.8[/tex]