The graphs you will encounter on the test are like the passages in that they are both written to make a main point. That point can often be “read” in a glance if you keep the following questions in mind:
The simplest graphs consist of one line, and they are intended simply to show change over time.
The graph shows that Houston’s population dropped between 2019 and 2021 and then rebounded beginning in 2021. Between 2021 and 2023, Houston’s population returned to the 2019 level by 2022 and then continued to grow, gaining roughly half a percentage point.
When a graph includes two lines, ask yourself:
According to the graph, which statement is true?
a. Houston and Phoenix lost people at about the same rate, but only Houston experienced a net loss of population.
b. The difference in population between Houston and Phoenix has never been smaller.
c. Houston’s population rate increased until 2021, when it began to shrink.
d. Phoenix’s population dropped more sharply between 2020 and 2021 than at any other time.
e. The populations of Houston and Phoenix have been roughly the same size since 2022.
Answer: Houston and Phoenix lost people at about the same rate, but only Houston experienced a net loss of population is correct because only the blue line, which represents Houston, dips below zero percent growth.
The difference in population between Houston and Phoenix has never been smaller is incorrect because the graph shows the population shifts in percentages, not in total numbers. We don’t know the population of either city because the graph only shows the percentage of change.
Houston’s population grew by more than one percent before beginning to drop in 2021 is incorrect because Houston was attracting fewer newcomers than it had in previous years.
Phoenix’s population dropped more sharply between 2020 and 2021 than at any other time is incorrect because there was a greater drop between 2021 and 2022.
The populations of Houston and Phoenix have been roughly the same size since 2022 is incorrect because the passage is about percentiles of change, not about overall population size.
Like line charts, area graphs show changes over time. However, they use colors to shade in the areas below or between lines to show how different variables performed during the same amount of time. Here’s an example:
Eileen Jackson’s third-grade class tracked their growth from September to June. She measured the children monthly and recorded each child’s growth. At the end of the year, the children studied the results. Both boys and girls grew at roughly similar rates for most of the year. Boys were taller than girls, but the difference between them was smaller in June than it was in September. Both groups experienced a slight peak in growth during the middle of the year, but the girls’ peak was more dramatic.
Which concluding sentence includes an accurate reading of the graph?
a. By the end of the year, boys and girls had both grown about three inches, although they did not grow at the same rate throughout the year.
b. By the end of the year, the boys had grown an average of three inches, and the girls averaged about two inches’ growth.
c. By the end of the year, girls were on pace to be taller than the boys by the following September.
d. By the end of the year, it was clear that girls grow faster than boys.
e. By the end of the year, most boys were taller than fifty inches.
Answer: By the end of the year, boys and girls had both grown about three inches, although they did not grow at the same rate throughout the year is correct because the girls grew more in the second half of the year than they did in the first half, whereas the boys grew at a steadier pace.
By the end of the year, the boys had grown an average of three inches, and the girls averaged about two inches’ growth is incorrect because the graph shows that the girls grew about four inches.
By the end of the year, girls were on pace to be taller than the boys by the following September is incorrect because the two groups were about the same distance apart for most of the year.
By the end of the year, it was clear that girls grow faster than boys is incorrect because the girls only grew more rapidly between February and April; the two groups were about the same distance apart for most of the year.
By the end of the year, most boys were taller than fifty inches is incorrect because the average height of most boys is just barely above fifty inches, which means that a number of boys were still below that height.
Sign up for free to take 5 quiz questions on this topic