Question

the equation for the line of best fit is f(x) ≈ 1.8x − 5.4 for the set of values in the table.

x	f(x)
5	2
6	5
6	6
8	8
9	7
10	18

using the equation for the line of best fit, what is a good approximation for x when f(x) = 30?
○ 14
○ 20
○ 45
○ 54

Explanation:

Step1: Substitute \( f(x) = 30 \) into the equation

We have the line of best fit equation \( f(x) \approx 1.8x - 5.4 \). Substitute \( f(x) = 30 \) into it:
\( 30 = 1.8x - 5.4 \)

Step2: Solve for \( x \)

First, add \( 5.4 \) to both sides of the equation:
\( 30 + 5.4 = 1.8x \)
\( 35.4 = 1.8x \)
Then, divide both sides by \( 1.8 \) to solve for \( x \):
\( x = \frac{35.4}{1.8} \approx 19.67 \approx 20 \)

Answer:

20