A line of best fit is f(x) ≈ −0.86x + 13.5 for the set of points in the table. A 2-column table with 7 rows. The first column is labeled x with entries 2, 3, 5, 6, 7, 8, 9. The second column is labeled f(x) with entries 12, 10, 10, 8, 9, 5, 6.

Using the equation for the line of best fit, what is a good approximation for the value of the function, f(x), when x = 18?

−5
−2
3
12