Measures of Center Worksheet
Choose and calculate mean, median, and mode. Includes a worked example, printable practice, and an answer key with explanations.
The answer key follows the practice below. In the editor, remove the final answer-key section before sharing a student copy.
Use This WorksheetIncludes
Standards
Topics
Measures of Center
Name:
Date:
Score:
Learning goal and worked example
Choose and calculate mean, median, and mode.
For {2,2,3,9}, mean = 16/4 = 4, median = (2+3)/2 = 2.5, and mode = 2. The unusually large 9 pulls the mean upward.
Review activity: sort first for the median. The mean need not be one of the observations.
Read each question carefully and provide the best answer. Show all your work where applicable.
1. Define the following terms in your own words:
a) Mean:
b) Median:
c) Mode:
2. Calculate the mean, median, and mode for the following data set:
Data set: {12, 15, 18, 12, 20, 22, 12, 15, 18}
Mean:
Median:
Mode:
3. Which measure of center is most affected by outliers?
Mean
Median
Mode
All of the above
4. After sorting an even number of numerical data points, how do you find the median?
The average of the two middle numbers
The largest number in the set
The smallest number in the set
There is no median
5. The is the value that appears most often in a data set.
6. To find the median, you must first the data from least to greatest.
7. A student scored the following on their math tests: 85, 92, 78, 85, 90. What is the mean test score?
8. Consider the data set: {5, 7, 10, 12, 15, 18}. Find the median.
9. Students A–F read 1, 3, 2, 4, 1, 5 books, respectively, as shown below. Calculate the mean, median, and mode of these six values.
Mean:
Median:
Mode:
Answer key and worked solutions
1a. Mean: sum divided by count. 1b. Median: middle sorted value, or average of the two middle values for an even count. 1c. Mode: most frequent value(s).
2. Sum = 144, count = 9, so mean = 16. Sorted data: 12,12,12,15,15,18,18,20,22; median = 15; mode = 12.
3. a (mean). 4. a (average of the two middle sorted values).
5. Mode. 6. Sort (or order).
7. (85+92+78+85+90)/5 = 430/5 = 86.
8. Median = (10+12)/2 = 11.
9. Books: 1,3,2,4,1,5; sum 16, mean = 16/6 = 8/3 ≈ 2.67 books. Sorted: 1,1,2,3,4,5; median = 2.5 books; mode = 1 book.
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