The table shows the number of songs that were downloaded and the total cost for buying the songs.

\begin{tabular}{|c|c|}
\hline
\multicolumn{2}{|c|}{Cost of Downloaded Songs} \\
\hline
\begin{tabular}{c}
Number of Songs \\
[tex]$( x )$[/tex]
\end{tabular} &
\begin{tabular}{c}
Total Cost (in [tex]$\$[/tex])$ \\
[tex]$( y )$[/tex]
\end{tabular} \\
\hline
2 & 4 \\
\hline
3 & 6 \\
\hline
4 & 8 \\
\hline
5 & 10 \\
\hline
\end{tabular}

What is the rate of change for the function in the table?

A. 2 songs for [tex]$\$[/tex]1$

B. [tex]$\$[/tex]2$ per song

C. 4 songs for [tex]$\$[/tex]1$

D. [tex]$\$[/tex]4$ per song



Answer :

To determine the rate of change for the cost of downloading songs given in your table, let's analyze the information step-by-step:

The table shows:
- When 2 songs are downloaded, the total cost is $4.
- When 3 songs are downloaded, the total cost is $6.
- When 4 songs are downloaded, the total cost is $8.
- When 5 songs are downloaded, the total cost is $10.

First, let's understand what the rate of change represents. The rate of change is essentially how much the cost (\( y \)) increases with each additional song (\( x \)). Mathematically, this is the change in \( y \) divided by the change in \( x \).

From the table, we can see how the costs change with the number of songs. To calculate it, we can use the values in the table:

Let's take the two endpoints:
- When \( x_1 = 2 \) and \( y_1 = 4 \)
- When \( x_2 = 5 \) and \( y_2 = 10 \)

The formula for the rate of change (slope) is:
[tex]\[ \text{Rate of Change} = \frac{\Delta y}{\Delta x} = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

Plugging the values from the table into the formula:
[tex]\[ \text{Rate of Change} = \frac{10 - 4}{5 - 2} = \frac{6}{3} = 2.0 \][/tex]

Therefore, the rate of change for the function in the table is \( 2.0 \). This means that the cost increases by \( \$2 \) for every additional song downloaded.

Thus, the correct interpretation of the rate of change from the given options is:
[tex]\[ \$2 \text{ per song} \][/tex]