Select the correct location on the image.

On the interval [tex]$[x, 7]$[/tex], at which [tex]$x$[/tex]-value is the average rate of change 56?

\begin{tabular}{|c|c|c|c|c|c|}
\hline
[tex]$x$[/tex] & 3 & 4 & 5 & 6 & 7 \\
\hline
[tex]$f(x)$[/tex] & 12 & 24 & 28 & 96 & 192 \\
\hline
\end{tabular}



Answer :

To determine at which [tex]\( x \)[/tex]-value the average rate of change on the interval [tex]\([x, 7]\)[/tex] is 56, we need to investigate each [tex]\( x \)[/tex]-value from the table and calculate the corresponding average rate of change.

The average rate of change of a function [tex]\( f \)[/tex] over the interval [tex]\([a, b]\)[/tex] is given by:
[tex]\[ \frac{f(b) - f(a)}{b - a} \][/tex]

Here, [tex]\( b = 7 \)[/tex] and [tex]\( f(b) = f(7) = 192 \)[/tex].

We will calculate the average rate of change for each [tex]\( x \)[/tex] from 3 to 6 (since 7 would just be the point itself and not an interval):

1. For [tex]\( x = 3 \)[/tex]:
[tex]\[ \text{Average rate of change} = \frac{f(7) - f(3)}{7 - 3} = \frac{192 - 12}{7 - 3} = \frac{180}{4} = 45 \][/tex]

2. For [tex]\( x = 4 \)[/tex]:
[tex]\[ \text{Average rate of change} = \frac{f(7) - f(4)}{7 - 4} = \frac{192 - 24}{7 - 4} = \frac{168}{3} = 56 \][/tex]

3. For [tex]\( x = 5 \)[/tex]:
[tex]\[ \text{Average rate of change} = \frac{f(7) - f(5)}{7 - 5} = \frac{192 - 28}{7 - 5} = \frac{164}{2} = 82 \][/tex]

4. For [tex]\( x = 6 \)[/tex]:
[tex]\[ \text{Average rate of change} = \frac{f(7) - f(6)}{7 - 6} = \frac{192 - 96}{7 - 6} = \frac{96}{1} = 96 \][/tex]

Among these calculations, the only [tex]\( x \)[/tex]-value for which the average rate of change is 56 is [tex]\( x = 4 \)[/tex].

Therefore, the correct location on the image where the average rate of change on the interval [tex]\([x, 7]\)[/tex] is 56 is at [tex]\( x = 4 \)[/tex].