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 $f(x)=30$? 14 20 45 54

Explanation:

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

Given \( f(x)=1.8x - 5.4 \), when \( f(x) = 30 \), we have the equation \( 30=1.8x - 5.4 \).

Step2: Solve for \( x \)

Add \( 5.4 \) to both sides of the equation:
\( 30 + 5.4=1.8x-5.4 + 5.4 \)
\( 35.4 = 1.8x \)
Then divide both sides by \( 1.8 \):
\( x=\frac{35.4}{1.8}=19.66\cdots\approx20 \)

Answer:

20