Explain if the following is a proportional relationship: Sam used 6 gallons of gas to drive 50 miles and 4 gallons of gas to drive 100 miles.

An unknown number x is at most 10. which graph best represents all the values of x? number line graph with closed circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the right. number line graph with open circle on 10 and shading to the left. number line graph with closed circle on 10 and shading to the left.