The table shows the cost y (in dollars) of x pounds of sunflower seeds.

a. What is the missing y-value that makes the table represent a linear function?

The missing y-value is

b. Write a linear function that represents the cost y of x pounds of seeds. Interpret the slope.

c. Does the function have a maximum value? Explain your reasoning.
The function _ have a maximum value because you _ increase the cost by increasing the amount of sunflower seeds purchased.