Question

A proportional relationship between the number of pounds of potatoes (x) and the price in dollars (y) is graphed, and the ordered pair (4, 3) is on the graphed line.
Part A: What is the price of 1 pound of potatoes? Show your work, including the proportion you used to determine the price. (8 points)
Part B: What does the ordered pair (8, 6) on the graph represent? Explain in words. (2 points)

Answer 1

Part A

We have x = 4 and y = 3 paired up together.

This says that 4 pounds of potatoes cost $3

The price per pound (aka unit price) is y/x = 3/4 = 0.75 dollars = 75 cents.

Answer: 75 cents per pound

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Part B

The ordered pair (8,6) means x = 8 and y = 6 pair up together.

So in this case, 8 pounds of potatoes cost $6.

notice how y/x = 6/8 = 3/4 = 0.75 dollars = 75 cents here as well. So we get the same unit cost.