6.4 Bar graphs and pie charts
Bar graphs use columns of varying heights instead of lines on a grid. They can be used to track data in multiple catefories at a time, as you can see in the graph below.
The graph shows the obesity rates among eighteen demographic groups from ages 2-19. These demographics vary according so sex, race, and age. The graph allows readers to compare between males and females of every age as well as by their age and membership in one of three racial groups. Let’s pair it with a passage:
Childhood obesity continues to rise, and this fact is even more concerning when one considers that more than half of obese children will become obese teens, eighty percent of whom will become obese adults. Obesity places children at risk for a number of physical and mental health problems, including diabetes, depression, asthma, and cardiovascular disease. Studies have shown that one third of obese toddlers will become obese children, and more than half of them will become obese teens. Eighty percent of obese teens will remain obese in adulthood.
Which comparison between demographic groups is supported by the graph?
a. Black, non-Hispanic males are less likely to be obese as toddlers as are White, non-Hispanic females.
b. Hispanic girls aged 6-11 are more likely to be obese than boys in the same age group.
c. White males are more likely to be obese as toddlers than they are as adolescents.
d. Black, non-Hispanic males are as likely to be obese in elementary school as they are in high school.
e. White females are more likely to be obese between ages 6-11 than they are as adolescents.
Answer: Black, non-Hispanic males are as likely to be obese in elementary school as they are in high school is correct because the green bar in both categories shows that the likelihood of obesity for boys in those two categories is about 22%.
Black, non-Hispanic males are less likely to be obese as toddlers as are White, non-Hispanic females is incorrect because the likelihood of obesity for Black boys is 15%, and White, non-Hispanic girls in the same age group only have a 12% likelihood of obesity.
Hispanic girls aged 6-11 are more likely to be obese than boys in the same age group is incorrect because Hispanic girls aged 6-11 have about a 26% chance of becoming obese, and Hispanic boys aged 6-11 have about a 28% chance.
_White males are more likely to be obese as toddlers than they are as adolescents_is incorrect because the obesity rate for White male toddlers.is 10%, whereas White male teens are about 18% likely to be obese.
White females are more likely to be obese between ages 6-11 than they are as adolescents is incorrect because they have a 19% chance of obesity from 6-11 and a 21% chance from 12-19.
Pie charts, not surprisingly, look like pies that have been divided into slices. However, not all of the slices are the same size. These different sizes make it easier for people to conceptualize numerical data in which the parts add up to 100%. When a pie chart is paired with a passage, you need to check each part of each answer choice for accuracy because wrong answers often misstate the data from one or the other.
Here’s an example:
A study on college student demographics found that students who grew up in the suburbs graduate college at higher rates than their urban and rural counterparts for a number of reasons. For example, they are more likely to have college-educated parents who can help them navigate the application process and transition into the college environment successfully. Rural and urban students, in contrast, are more likely to be the first in their families to attend college, and that means that they are not as well prepared as their suburban counterparts. Their academic skills may be weaker because they are more likely to have attended understaffed, underfunded schools than suburban students are, and they are also more likely to come from poor families. Additionally, urban and rural students don’t always have reliable internet connectivity. The colleges they attend may be prohibitively far from where they live, and this can create insurmountable problems. They may lack reliable transportation but also be unable to afford to live on or near campus. As a result, although about 80% of urban students graduate from high school, only 30% actually graduate. Rural students have a 90% graduation rate from high school but only about 30% will earn their degrees.
What is the relationship between the passage and the graph?
a. Both the passage and the pie consider how location affects college attendance, but only the passage mentions other factors.
b. The pie chart clarifies the claims made in the passage.
c. The passage and the pie chart both provide reasons for why some students leave college without finishing their degrees.
d. The passage provides less specific demographic information about who enrolls in college than the pie chart does.
e. The information that the graph provides is neutral, whereas the passage expresses strong opinions.
Answer: Both the passage and the pie consider how location affects college attendance, but only the passage mentions other factors is correct. It accurately summarizes what each says.
The pie chart clarifies the claims made in the passage is incorrect because the passage is more detailed than the pie chart. The chart only illustrates one of the passage’s points.
The passage and the pie chart both provide reasons for why some students leave college without finishing their degrees is incorrect because the pie chart only provides information about one reason–location–that can prevent college completion.
The passage provides less specific demographic information about who enrolls in college than the pie chart does is incorrect because the passage provides more detail about various demographic groups.
The information that the passage provides is neutral, whereas the pie chart expresses strong opinions is incorrect because the pie chart simply provides information without comment.