GED and HiSET mathematics — reading charts, graphs and tables

Many questions on the GED Mathematical Reasoning test and the HiSET Mathematics test start from a picture of data rather than a list of numbers: a bar graph of sales, a line graph of bills, a circle graph of a budget, a scatter plot, a box plot or a table. Reading the display correctly is half the question, and most wrong answers come from reading the wrong bar, the wrong segment or the wrong part of the box. This material puts the displays on screen and trains you to read each one quickly and accurately.

The twelve quiz questions each use a different display or skill. A bar graph of a hardware store's week asks how much better the best day was than the worst. A double bar graph compares two doctors' patient counts month by month. A line graph of an electric bill asks where the steepest rise happened, and a separate question turns a change in fuel cost into a percent increase. A circle graph splits a 3,200-dollar monthly budget, and another circle-graph question converts a percent into a central angle. A scatter plot of used cars shows how price falls with age, and a trend line equation is used to make a prediction. Two box plots ask for the median, the interquartile range and the share of the data above the third quartile. A frequency table asks for the mode and the weighted mean, and the last question asks which display suits a given purpose.

Every display is also described in words and numbers, so the questions can be answered by screen readers and in the spoken exam. Wrong options come from the usual misreadings: taking the first bar for the smallest, reading the range where the interquartile range is asked, taking the highest point for the biggest rise, or averaging values without their frequencies. The explanations point to the exact place in the display where the misreading happens.

The flashcards define each type of display and the key ideas behind them: central angles, positive, negative and no correlation, trend lines, correlation versus causation, the five-number summary, the interquartile range, dot plots and histograms.

The written work asks you to interpret displays in full sentences with the numbers that support each claim: comparing two series, describing a trend, finding a percent change, reading a box plot, spotting a misleading scale and choosing a display. The oral exam asks one question at a time about a display described in words.

The material is independent practice written by Zestly, based on the published content of the GED and HiSET mathematics tests; it is not produced or endorsed by GED Testing Service or ETS.

• Read and compare values in bar graphs and double bar graphs
• Find changes and percent changes in a line graph
• Convert circle-graph percents into amounts and central angles
• Describe the correlation in a scatter plot and use a trend line to predict
• Read the median, quartiles and interquartile range from a box plot
• Find the mode and weighted mean from a frequency table
• Choose an appropriate display for parts of a whole, change over time or a relationship between two variables

Practice material written by Zestly, based on the published content of the GED Mathematical Reasoning test (data analysis: interpreting bar graphs, line graphs, circle graphs, scatter plots, box plots, dot plots and tables) and the HiSET Mathematics test (data analysis, probability and statistics).