Points leak in small, specific ways: a mean divided by five when the table has six rows, a median taken from an unsorted list, two probabilities added when both events had to happen. Each slip produces a tidy number planted among the choices, and a GED Testing Service session on skill gaps names compound probability as one of four areas testers miss.
On the score report this topic sits inside “quantitative problem solving in measurement”, the category GED Testing Service weights at about 20% and shares with geometry. Split it evenly across about 46 questions and data comes to roughly four to six items, our arithmetic on the published weight rather than an official count.
Skills in this set: Mean of a data set · Mean of a data set shown in a table · Median of a data set with an even number of values · Mode and range from a dot plot · Finding a missing value from a required mean · Weighted average · Comparing categories on a bar graph · Totals and differences from a two-column table · Reading counts from a dot plot · Reading a circle graph given as percents · Probability of a single event and comparing likelihoods · Probability of the complement of an event · Probability of two independent events · Probability of two dependent events (no replacement) · Counting outcomes with the multiplication principle · Comparing the center and spread of two data sets
What the test asks
The Assessment Guide for Educators lists the data indicators as Q.6.a through Q.8.b. In plain terms: bar graphs and circle graphs (Q.6.a); dot plots, histograms and box plots (Q.6.b); two-variable tables, line graphs and scatter plots (Q.6.c); mean, median, mode and range, including a missing value for a target mean and weighted averages (Q.7.a); counting outcomes, including combinations and permutations (Q.8.a); and single and compound probability (Q.8.b). The guide adds that two or three questions can share one table or graph.
Settings are everyday counts: quiz scores, shift hours, a survey of how students get to school drawn as a circle graph, tiles pulled from a bag. A weighted average arrives as a course grade where homework counts 20%, quizzes 30% and the final 50%. Probability questions almost always say whether the first item is put back, and that phrase decides the whole calculation.
Nothing in the official record says which topics fill the roughly five no-calculator questions that open the test, but reading two bars and subtracting, or writing 4 out of 12 as a probability, needs no calculator, so expect that it can. A weighted grade belongs with the calculator, whose fraction key reduces 30/132 to 5/22 for you.
The mistakes this set is built to catch
Each wrong answer in the practice set is the result of one specific slip, and the explanation names it. These are the ones that come up most in this topic.
1Dividing by the wrong count
The sheet gives the mean as the sum of the values divided by the number of values, and the dividing is where the marks go. Six rows added and divided by five gives a number that looks like an average and sits among the choices; so does dividing by seven. Count the rows and write that number down before you add.
2Finding the median before sorting
The median is the middle of an ordered list, and tables on the test are almost never in order. Averaging the two numbers that happen to sit in the middle rows gives a value the set deliberately offers as a choice. Rewrite the list from least to greatest first; with an even count, average the two middle values rather than picking one.
3Adding probabilities that should be multiplied
When a question asks for the chance that the first bead is red and the second is blue, both things have to happen, so the probabilities multiply. Adding them answers a different question, one or the other, and gives a fraction bigger than either event alone. Circle the word “and” as you read; if it is there, multiply.
4Forgetting the bag shrinks when nothing goes back
If the first tile stays out, the second draw comes from a smaller bag: one fewer tile of that color on top, one fewer in total underneath. From 6 blue out of 12, the second draw is 5 out of 11. The set offers 6/12 × 6/12, which treats the tile as replaced, and two options that shrink only one of the numbers.
A worked example
A jar holds 4 red, 6 blue and 2 green beads. Two are taken out one after the other without looking, and the first is not put back. What is the probability that both are blue?
Count the total, then the first draw
Probability is favorable outcomes over total outcomes: 6 of the 12 beads are blue.
4 + 6 + 2 = 12; P(first blue) = 6/12
Update the jar for the second draw
One blue bead is gone and stays gone, so 5 blue remain out of 11.
P(second blue) = 5/11
Multiply, since both must be blue
Both events have to happen, so multiply tops together and bottoms together, leaving the fraction unsimplified so you can see where it came from.
6/12 × 5/11 = 30/132
Simplify and check the size
Divide top and bottom by 6 to simplify. With the bead put back the answer would be 6/12 × 6/12 = 1/4, so the real answer should be a little less.
30/132 = 5/22, or about 0.23
Answer: 5/22, or about 0.23
How to practice it
- Write the count before the total. When a question asks for a mean, count the values in the table, write “÷ 6” on your note board, and only then start adding. That habit stops the six-becomes-five slip.
- Sort the list first, every single time. For a median, mode or range, rewrite the values from least to greatest and cross off from both ends: what is left in the middle is the median, whatever repeats most is the mode, and last minus first is the range.
- Ask one question on every two-draw problem: did it go back? If yes, the second fraction matches the first; if no, take one off the top and one off the bottom. Write both fractions side by side, favorable over total, then multiply straight across.
- Read the scale before the bars. On a bar graph, work out what one gridline is worth before reading any height; on a dot plot, underline “more than 3” or “3 or more” and decide whether the column at 3 counts before you start.
Frequently asked questions
Are mean and median on the GED formula sheet?
Yes, both. The sheet defines the mean as sum divided by count, and the median as the middle value of an ordered list, or the average of the two middle values for an even count. Mode (most frequent value) and range (largest minus smallest) are not on it.
Is probability on the GED formula sheet?
No. The sheet has no probability or counting formulas, so carry four ideas with you: probability is favorable over total; the chance of not happening is 1 minus the chance of happening; when both events must happen, multiply; and when the first item is kept out, both parts of the second fraction shrink by one.
How many statistics and probability questions are on the GED math test?
GED Testing Service does not publish a count per topic. Data shares the 20% measurement category with geometry, so on about 46 questions an even split gives four to six data items. That split is our assumption; the official record does not say how the category divides.
Do I need combinations and permutations for the GED?
Indicator Q.8.a lists counting methods including combinations and permutations, so they are in scope, though the official record does not say how often they appear or whether a formula is expected. The practice set concentrates on the counting principle: multiply the choices in each category, as in a lunch special of bread, filling and drink.
Sources
Figures on this page were checked against these sources on the dates shown.
- Assessment Guide for Educators: Mathematical Reasoning · GED Testing Service · checked September 13, 2026
- Mathematics Formula Sheet (2026-02 revised) · GED Testing Service · checked September 13, 2026
Keep going
The formula sheet, explained
Mean and median on the sheet, and the probability rules you bring with you.
Fractions, decimals and percents practice
Probabilities are fractions and circle graphs are percents; the conversions matter here.
Geometry and measurement practice
The other half of the measurement category, worth practicing alongside data.