At the deli counter in the supermarket, Nigel paid $10 for 2 1/2 pounds of roast beef. The cost of deli meat is proportional to its weight. What is the equation for the graph of this proportional relationship?

y = x

The equation for the graph of this proportional relationship is y = x. The variable x represents the weight of the deli meat in pounds, and the variable y represents the cost of the deli meat in dollars. Since the cost of deli meat is proportional to its weight, the equation for the proportional relationship is simply y = x.

The equation for the graph of this proportional relationship is obtained by setting the cost, represented by y, equal to the weight, represented by x. Therefore, the equation is y = x.

To determine the equation for the graph of this proportional relationship, we need to consider the given information.

From the problem, we know that Nigel paid $10 for 2 1/2 pounds of roast beef.

Let's define the variables:
- Let y represent the total cost of the deli meat.
- Let x represent the weight of the deli meat.

Since the cost of deli meat is proportional to its weight, we can write the equation as follows:

y = kx

Where k is the constant of proportionality.

To find the value of k, we can use the given information. We know that Nigel paid $10 for 2 1/2 pounds of roast beef.

So, we can substitute these values into the equation:

10 = k * 2.5

Now, we can solve for k by dividing both sides of the equation by 2.5:

k = 10 / 2.5
k = 4

Therefore, the equation for the graph of this proportional relationship is:

y = 4x