Watch the video version of this episode on YouTube - https://youtu.be/GRrY3a9ZqI0 

A physical therapist reviews a data set that is heavily influenced by extreme scores. Which measure of central tendency would be MOST affected by this type of data?

1. Mean
2. Median 
3. Mode 
4. Range 

Transcript

Welcome back to the Scorebuilders’ Question and Answer Podcast! This podcast provides members of the Scorebuilders’ team with the opportunity to explore challenging multiple-choice examination questions with students actively preparing for the licensing examination. My name is Scott Giles and I will be your host for today’s journey.

Ready? Let’s go!

A physical therapist reviews a data set that is heavily influenced by extreme scores. Which measure of central tendency would be MOST affected by this type of data?

1. Mean
2. Median 
3. Mode 
4. Range 

Measures of Central Tendency
Measures of central tendency are summary measures that attempt to describe a set of data with a single value that represents the middle or center of its distribution. Measures of central tendency include the mean, median, and mode.

Let’s explore each of the options:

Option 1 - Mean 
The mean is the arithmetic average and is determined by taking the sum of all values and dividing that number by the number of values. 

As a result, the mean would be affected by extreme scores since the scores would influence the sum of all values. The magnitude of the change in the mean would be based on how extreme the values were and whether they were unidirectional or bidirectional.

Option 2 - Median 
The median is the point on a distribution at which 50% of the values fall above and below. 

The median is determined by first rank ordering the values. If the number of values is odd, the median is the middle value. If the number of values is even, the median is the mean of the two middle values. 

The median is less affected by extreme scores than the mean since the mean takes into account every single data point including extreme values. This fact can significantly move the mean value in one direction or the other, whereas the median remains relatively stable even if extreme values are present.

Option 3 - Mode 
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The mode is the value that occurs most frequently within a data set. 

A distribution with two modes is termed bimodal. A distribution with more than two modes is termed multimodal. The mode would not typically be influenced by extreme scores since it’s determined solely by the value occurring most frequently.

Option 4 - Range 
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The range is the difference between the maximum and minimum values. 

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Extreme scores could influence the minimum and maximum values. This would influence the range; however, the range is not considered a measure of central tendency.

The correct answer is Option 1

Let’s explore the all student data:
62% of students selected Option 1, Mean, the correct response
20% of students selected Option 2, Median
7% of students selected Option 3, Mode
11% of students selected Option 4, Range

System Classification
This question is a Non-Systems question which represents approximately 14% of all exam items.

Content Outline Classification
This question is a Safety and Protection; Professional Responsibilities; Research question which represents approximately 8% of all exam items.

Level Classification
This question is a Level 1 question since the question requires students to possess basic foundational academic knowledge. Remediation of Level 1 questions occurs through academic review of entry-level content using textbooks, review books, Basecamp, and flash cards.

Academic Focus Area
Looking to review related academic content? Check out page 839 in PTEXAM: The Complete Study Guide.

Thanks for joining us on the Scorebuilders Q and A podcast! See you next week!