Calculating the Mean (Average): TEAS Practice Question with Answer & Explanation

Understanding the Mean in Statistics

To find the mean (often referred to as the average) of a data set, you must follow a two-step mathematical process. This is a fundamental skill for the TEAS Math section, particularly within the Statistics and Data interpretation category.

Step 1: Sum the Data Points

First, add all the values in the data set together:

• $72 + 88 + 94 + 75 + 80 + 78 + 92 + 73 = 652$

Step 2: Divide by the Count

Next, count how many numbers are in the set. In this case, there are 8 quiz scores. Divide the total sum by that count:

• $652 \div 8 = 81.5$

Therefore, the mean quiz score is 81.5.

Analysis of Incorrect Answers

• Choice A (85.5): This is a distracter that might result from a simple addition error or accidentally dividing the sum by 7 instead of 8.
• Choice B (82.0): This is the median of the data set. To find the median, you would arrange the scores in order (72, 73, 75, 78, 80, 88, 92, 94) and average the two middle numbers (78 and 80). While the median is a measure of central tendency, it is not the mean.
• Choice D (83.0): This is a common "estimate" error. Many students try to guess the middle based on the highest and lowest values, but this does not provide the mathematical mean of the entire set.

TEAS Concept: Measures of Central Tendency

Nursing students must understand how to interpret patient data, such as average heart rates or mean arterial pressure. The TEAS tests your ability to distinguish between:

• Mean: The mathematical average (Sum $\div$ Count).
• Median: The middle value when numbers are ordered least to greatest.
• Mode: The value that appears most frequently.
• Range: The difference between the highest and lowest values ($94 - 72 = 22$ in this set).

Memory Tip

Think of the word "MEAN" as being the most "demanding" or "mean" calculation because it requires the most work: you have to add everything up AND divide! The "Mode" starts with MO, just like the "Most" frequent number.