Suppose that the distance a car travels varies directly with the amount of gasoline it uses. A certain car uses 25 gallons of gasoline to travel 800 miles. If the car travels 608 miles, how much gasoline does it need? gallons

Step 1 ：D = k * G

Step 2 ：800 = k * 25

Step 3 ：k = 800/25

Step 4 ：k = 32

Step 5 ：608 = 32 * G

Step 6 ：G = 608/32

Step 7 ：G = 19

Step 8 ：\(\boxed{19}\) gallons of gasoline are needed to travel 608 miles.