Atest car travels in a straight line along the x axis. the graph in the figure shows the car's position x as a function of time

It is regretful to note that you have not included here the graph that would represent the car's position as a function of time. I think for this item, you will be asked to determine the position of the car at a certain time t. Note that most of the time, the independent variable is graph in the x-axis and the dependent one is graphed in the y - axis. 

45 miles = 60 minutes

1 mile = 60/45 = 4/3 = 1.33 minutes