GED Math Extra Prep: Mean, Median, and Mode

Some questions on the GED Math test will ask you to extract information from a collection of data. For example, you might have to find the mean, median, or mode—and sometimes all three.

Practice Questions

Both questions are based on the following information.

Ten students took a math quiz that consisted of 10 questions. The median score was 5.5. The modal score was 6. The teacher recorded the results of the first nine students in the following line plot.

1. What was the average score of the first nine students whose scores were represented on the line plot? Give your answer to one decimal place. A. 4.9 B. 5.4 C. 5.5 D. 5.7
2. What score did the tenth student get in the quiz? A. 4 B. 5 C. 6 D. 7

Answers and Explanations

1. The correct answer is B.

   The sum of the nine scores that were plotted on the line graph is 49: 2 + 3 + 4 + 4 + 5 + 6 + 6 + 9 + 10 = 49. Dividing the sum by 9 gives you

   

   Rounding to one decimal place gives you 5.4, so Choice (B) is the correct answer.

2. The correct answer is C.

   Because the modal score (the mode) is 6, more students must have scored a 6 than any other score. Hence, the tenth student must have also scored 6.

   You can also check that this score gives the correct median by placing all the scores in ascending order and picking the average of the middle two numbers.

   2, 3, 4, 4, 5, 6, 6, 6, 9, 10

   The middle two numbers are 5 and 6, so the median is