GED Mathematical Reasoning – Data Analysis, Statistics, and Probability — Questions and Answers
Question 1: The test scores for five students are: 72, 85, 90, 85, and 68. What is the median score?
- 80
- 85 (Correct answer)
- 72
- 90
Correct answer: 85
To find the median, arrange the scores in order: 68, 72, 85, 85, 90. The median is the middle value in an ordered list of five numbers, which is the third value: 85. The mean would be (72+85+90+85+68)÷5 = 400÷5 = 80, which is different from the median.
Question 2: A bag contains 4 red marbles, 3 blue marbles, and 3 green marbles. If one marble is chosen at random, what is the probability it is blue?
- 1/3
- 3/10 (Correct answer)
- 3/7
- 7/10
Correct answer: 3/10
Probability = favorable outcomes ÷ total outcomes. There are 3 blue marbles and 10 total marbles (4+3+3), so the probability is 3/10. It is not 1/3 because 3 blue out of 10 total is not the same as 1 out of 3.
Question 3: A bar graph shows that a store sold 40 units in January, 55 in February, 35 in March, and 50 in April. What was the mean (average) number of units sold per month?
- 40
- 45 (Correct answer)
- 50
- 55
Correct answer: 45
Mean = sum of all values ÷ number of values. Sum = 40+55+35+50 = 180. Number of months = 4. Mean = 180÷4 = 45 units per month.
Question 4: In a data set, the value that appears most frequently is called the:
- mean
- median
- mode (Correct answer)
- range
Correct answer: mode
The mode is the value that appears most often in a data set. The mean is the arithmetic average, the median is the middle value when data is ordered, and the range is the difference between the largest and smallest values.
Question 5: A scatter plot shows a strong positive correlation between hours studied and exam scores. Which conclusion is best supported by this data?
- Students who study more tend to score higher on exams (Correct answer)
- Studying more hours causes students to score higher
- All students who study 10 hours will score 100%
- There is no relationship between studying and scores
Correct answer: Students who study more tend to score higher on exams
A positive correlation means that as one variable increases, the other tends to increase as well — students who study more hours tend to score higher. However, correlation does not prove causation (answer B), does not guarantee exact outcomes (answer C), and is the opposite of no relationship (answer D).
Question 6: A spinner has 8 equal sections numbered 1 through 8. What is the probability of spinning an even number?
- 1/4
- 1/2 (Correct answer)
- 3/8
- 5/8
Correct answer: 1/2
The even numbers from 1 to 8 are: 2, 4, 6, and 8 — that's 4 even numbers out of 8 total sections. Probability = 4/8 = 1/2.
GED Mathematical Reasoning – Data Analysis, Statistics, and Probability
The test scores for five students are: 72, 85, 90, 85, and 68.
What is the median score?