Question

The equation for the line of best fit is f(x) ≈ 1.8x − 5.4 for the set of values in the table. Using the equation for the line of best fit, what is a good approximation for x when f(x) = 30?

Answer 1

20

Explanation:

Answer 2

We need to solve the equation for x:
f(x) ≈ 1.8x − 5.4
f(x) = 30

Then 1.8x − 5.4 = 30
1.8x = 30+5.4
1.8x = 35.4
x = 35.4/1.8
x = 19.66

Using the equation for the line of best fit, a good approximation for x is 20.