At the daily counter in the supermarket natural paid $10 for two and a half pounds of roast beef the cost of the daily meat is proportional to its way what is the equation for the graph of this proportional relationship

1 answer

To find the equation representing the proportional relationship between the cost of roast beef and its weight, we start by using the information given:

  • Natural paid $10 for 2.5 pounds of roast beef.

We can set up the relationship as follows:

  1. Let \( C \) represent the cost (in dollars).
  2. Let \( W \) represent the weight (in pounds).
  3. The problem states that the cost is proportional to the weight, which can be written in the form: \[ C = kW \] where \( k \) is the constant of proportionality (price per pound).

Next, we need to find the value of \( k \):

  • We know \( C = 10 \) when \( W = 2.5 \).

From the equation: \[ 10 = k \times 2.5 \]

To solve for \( k \): \[ k = \frac{10}{2.5} = 4 \]

Now that we have determined \( k \), we can write the equation that describes the relationship: \[ C = 4W \]

This equation states that the cost \( C \) in dollars is 4 times the weight \( W \) of the roast beef in pounds.