Determine whether each linear function is a direct variation. If so,
state the constant of variation.
4. Gallons, x 6 8 10 12
Miles, y 180 240 300 360
5. Time (min), x 10 11 12 13
Temperature, y 82 83 84 85
6. Number of Payments, x 6 11 16 21
Amount Paid, y $1,500 $2,750 $4,000 $5,250
