We know that x refers to the number of packs of trading cards, and y refers to the total cost of online orders.
So, the pair (4,28) means Jasper gets 4 packs of cards for $28.
The pair (10,64) means Jasper gets 10 packs of cards for $64.
Then, we find the range of change using the following formula.
Hence, the rate of change is 6, it means Jasper pays $6 per pack of trading cards.