Okay, let's solve this step-by-step:
Original price of 4 tires: $638
New price of 4 tires: $523
To calculate the percent change, we use the formula:
Percent Change = (New Price - Original Price) / Original Price
So in this case:
Percent Change = ($523 - $638) / $638 = -$115 / $638 = -0.18 = 18%
Since the new price is less than the original price, this is a decrease.
Therefore, the answer is A: 18% decrease
So the answer is A: 18% decrease