Final answer:
To determine the new price per gallon after a 6% reduction, first calculate the original price per gallon by dividing the total cost by the number of gallons. Then, find the amount of discount by multiplying the original price by 0.06. Subtract the discount from the original price to find the new price per gallon, which is approximately $2.90.
Step-by-step explanation:
The question involves calculating the new price per gallon after a discount at a gas station. Cassie paid $20.39 for 6.6 gallons on her third stop, which gives us the original price per gallon. To find the original price per gallon, we divide the total cost by the number of gallons, which is $20.39 / 6.6 gallons ≈ $3.09 per gallon. To calculate the new price after a 6% reduction, we multiply the original price by the percentage decrease: $3.09 * 0.06 = $0.1854. Subtracting this amount from the original price gives us the new price per gallon: $3.09 - $0.1854 = $2.9046. Therefore, after lowering their price by 6%, the gas station's new price per gallon will be approximately $2.90.