Question

students are selling t - shirts for a school fundraiser. the table shows the amount they raise.
shirts sold: 1, 2, 3, 4
amount raised (dollars): 4, 8, 12, 16
amount raised = 4·number of shirts
y = 4x
what is the constant of proportionality in dollars per shirt?
the constant of proportionality is

Explanation:

Step1: Recall the formula for proportionality

The general form of a proportional relationship is \( y = kx \), where \( k \) is the constant of proportionality.

Step2: Identify \( k \) from the given equation

We are given the equation \( y = 4x \), where \( y \) is the amount raised (in dollars) and \( x \) is the number of shirts sold. Comparing with \( y = kx \), we can see that \( k = 4 \). We can also verify this from the table: for \( x = 1 \), \( y = 4 \), so \( k=\frac{y}{x}=\frac{4}{1} = 4 \); for \( x = 2 \), \( y = 8 \), so \( k=\frac{8}{2}=4 \), and so on.

Answer:

4