Answer:
![r=4](https://tex.z-dn.net/?f=r%3D4)
![f(t)=4t](https://tex.z-dn.net/?f=f%28t%29%3D4t)
48 mililiters.
Step-by-step explanation:
We can find the rate of change using the given table.
The formula of the rate of change is
![r=\frac{y_{2}-y_{1} }{x_{2}-x_{1} }](https://tex.z-dn.net/?f=r%3D%5Cfrac%7By_%7B2%7D-y_%7B1%7D%20%20%7D%7Bx_%7B2%7D-x_%7B1%7D%20%20%7D)
Where we are gonna use points (3.5, 14) and (4.5, 18). Replacing these coordinates we have
![r=\frac{18-14}{4.5-3.5} =\frac{4}{1} =4](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B18-14%7D%7B4.5-3.5%7D%20%3D%5Cfrac%7B4%7D%7B1%7D%20%3D4)
Therefore, the average rate of change is 4 mililiters per hour.
Now, to find the function, we need to use the rate, a pair and the point-slope formula
![y-y_{1} =m(x-x_{1} )\\y-14=4(x-3.5)\\y=4x-14+14\\y=4x](https://tex.z-dn.net/?f=y-y_%7B1%7D%20%3Dm%28x-x_%7B1%7D%20%29%5C%5Cy-14%3D4%28x-3.5%29%5C%5Cy%3D4x-14%2B14%5C%5Cy%3D4x)
Therefore, the function which models this table, using the proper variables, is
![f(t)=4t](https://tex.z-dn.net/?f=f%28t%29%3D4t)
At last, we need to find the amount of water leaked after 12 hours.
![f(12)=4(12)=48](https://tex.z-dn.net/?f=f%2812%29%3D4%2812%29%3D48)
Therefore, after 12 hours it leaks 48 mililiters of water.