The table below shows the cost of downloading songs from a website.

Question

Number of SongsNumber of Songs Total CostTotal Cost
66 dollar sign, 1, point, 8, 0$1.80
1212 dollar sign, 3, point, 6, 0$3.60
2020 dollar sign, 6$6
What is the constant of proportionality between the total cost and the number of songs?

Answer 1

To find the constant of proportionality between the total cost and the number of songs, we can use the formula:

\[ k = \frac{\text{Total Cost}}{\text{Number of Songs}} \]

We can use any pair from the data provided. Let's evaluate all pairs:

1. For 6 songs costing $1.80: \[ k = \frac{1.80}{6} = 0.30 \]

2. For 12 songs costing $3.60: \[ k = \frac{3.60}{12} = 0.30 \]

3. For 20 songs costing $6.00: \[ k = \frac{6.00}{20} = 0.30 \]

In all cases, the constant of proportionality \( k \) is \( 0.30 \).

Therefore, the constant of proportionality between the total cost and the number of songs is $0.30 per song.