SAT Practice Questions: Reading Multiple Graphs

By Ron Woldoff

On the SAT Math exam, you may encounter a question that contains not one graph, but two. These kinds of questions ask you to explore the relationship between the two graphs, as in the following practice questions where you compare cold cereal sales in different counties.

Practice questions

Both questions are based on the following information.


  1. If the total 2013 cold cereal sales for the seven counties assessed were $150,000, what percent of these sales was purchased by Humboldt County? Disregard the percentage symbol when choosing your answer.
    A. 22
    B. 24
    C. 26
    D. 27
  2. If residents of Glenn County primarily purchase the Lucky Shapes brand cereal and residents of Trinity County primarily purchase the Sugar Choc brand cereal, what is the approximate ratio of the number of boxes sold in Glenn County to the number of boxes sold in Trinity County?
    A. 5:1
    B. 3:1
    C. 1:1
    D. 1:3

Answers and explanations

  1. The correct answer is Choice (B).
    If total sales were $150,000 and Humboldt County spent $36,000, you can find the percent by placing the Humboldt County sales over the total sales:
  2. The correct answer is Choice (C).
    Though actual numbers aren’t provided, you can use the column graph to approximate the ratios. Because the question asks for an “approximate” answer and the answer choices are far apart, you can eyeball your numbers from the graphs.
    Lucky Shapes and Sugar Choc show similar numbers of units sold, but the Sugar Choc sales dollars is about three times that of Lucky Shapes. This means, box for box, Sugar Choc costs approximately three times as much as Lucky Shapes.
    If the Trinity County spending (at $27,000) is three times that of Glenn County (at $9,000), and if the Trinity cereal box costs three times the Glenn cereal box, then the two counties are purchasing approximately the same number of cereal boxes.