Question 1 asks you to look at a line representing how far Manuel walks (y-axis) based on how long he's been walking (x-axis). Because it's a straight line, you know he walks at constant speed. Then, you have to look at other data points to determine which of them would also appear on that line. As with all graphs, if you have two numbers in parenthesis separated by a comma, the first number represents a value on the X axis and the second number represents the corresponding value on the Y axis.
So, let's look at the line and see if we can determine any point on the line. At X=1, the line crosses Y=6, so in 1 hour (the X Value), Manuel walks 6 miles (the Y value). To determine which of the four answers would also be on this line, compare each ordered pair as a ratio to 1 (x-value) and determine which of the four equals 1/6.
6 (y-value)
Only Choice (D): (1.5,9) works.
Question 7 gives you a graph with just numbers -- no units, no label for the axes -- and asks you to determine what customary units of measurement it could possibly apply to. In order to do this, you have to figure out what the relationship is between whatever is on the X axis to whatever is on the Y axis.
Looking at the line, when x=1, y =4 and when x=2, y=8. So, you are looking for units of measurement in which 4 of 1 thing = 1 of the other. On page 186, under Customary Measurements, the Capacity column tells you that 4 qt = 1 gal and 4 cups = 1 qt. Since Question 7 says 2 pairs of units can be represented, they must be:
X-axis: Gallons, Y-axis: Quarts and
X-axis: Quarts, Y-axis: Cups
Brown J.
12/24/14