Question

a line of best fit is f(x) = -0.86x + 13.5 for the set of points in the table. 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?

x	f(x)
3	10
5	10
6	8
7	9
8	5
9	6

-5
-2
3

Explanation:

Step1: Substitute x=18 into f(x)

$f(18) = -0.86 \times 18 + 13.5$

Step2: Calculate -0.86×18

$-0.86 \times 18 = -15.48$

Step3: Add 13.5 to result

$-15.48 + 13.5 = -1.98 \approx -2$

Answer:

B. -2