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 )?

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:
\( x = \frac{35.4}{1.8} \approx 19.67 \)

Since 19.67 is approximately 20, we can conclude that a good approximation for x is 20.

Answer:

20 (corresponding to the option "20")