Question

Marques was comparing the price of chicken breast at two stores. The graph below represents the total cost, in dollars and cents, yy, that it costs for xx pounds of chicken breast at SuperGrocery B.
0
Pounds
Total Cost (Dollars)
x
y
0
Pounds
Total Cost (Dollars)
(5,$36.30)
(10,$72.60)
SuperGrocery B
The table below represents the total cost, in dollars and cents, yy, that it costs for xx pounds of chicken breast at SuperGrocery A.
SuperGrocery A
Pounds left parenthesis x right parenthesisPounds (x) Total Cost left parenthesis y right parenthesisTotal Cost (y)
22 dollar sign, 19, point, 7, 6$19.76
33 dollar sign, 29, point, 6, 4$29.64
44 dollar sign, 39, point, 5, 2$39.52
55 dollar sign, 49, point, 4, 0$49.40
How much more expensive is it, per pound, to buy chicken breast at SuperGrocery A than at SuperGrocery B?

Answer 1

Find each store's unit price (dollars per pound).

- SuperGrocery B: slope = (72.60 − 36.30)/(10 − 5) = 36.30/5 = $7.26 per pound.
- SuperGrocery A: from the table y/x = 19.76/2 = 9.88 (and similarly for other rows) = $9.88 per pound.

Difference: 9.88 − 7.26 = $2.62.

So SuperGrocery A is $2.62 more expensive per pound.