Skip to main content
Ch. 2 - Descriptive Statistics
Larson - Elementary Statistics: Picturing the World 8th Edition
Larson8th EditionElementary Statistics: Picturing the WorldISBN: 9780137493470Not the one you use?Change textbook
Chapter 2, Problem 2.3.39

In Exercises 37– 40, without performing any calculations, determine which measure of central tendency best represents the graphed data. Explain your reasoning.
Bar graph showing heart rates of adults, with frequency on the y-axis and heart rate in beats per minute on the x-axis.

Verified step by step guidance
1
Step 1: Observe the graph and note that the data is unimodal and symmetric, meaning it has one peak and the distribution is roughly balanced on both sides of the center.
Step 2: Recall the three measures of central tendency: mean, median, and mode. The mean is the average of all data points, the median is the middle value when data is ordered, and the mode is the most frequently occurring value.
Step 3: For symmetric distributions, the mean is typically the best measure of central tendency because it takes into account all data points and reflects the center of the distribution accurately.
Step 4: The mode, which represents the most frequent heart rate, could also be considered, but it may not fully represent the center of the data if the distribution is symmetric.
Step 5: Conclude that the mean is the best measure of central tendency for this data because the graph is symmetric and unimodal, ensuring the mean accurately represents the center of the distribution.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Measures of Central Tendency

Measures of central tendency, including the mean, median, and mode, summarize a set of data by identifying the central point within that data. The mean is the average, the median is the middle value when data is ordered, and the mode is the most frequently occurring value. Each measure provides different insights, making it essential to choose the one that best represents the data's distribution.
Recommended video:
Guided course
04:52
Calculating the Mean

Distribution Shape

The shape of a data distribution, such as normal, skewed, or uniform, influences which measure of central tendency is most appropriate. For instance, in a normal distribution, the mean, median, and mode are similar, while in a skewed distribution, the mean may be pulled in the direction of the skew, making the median a better representative of the central tendency.
Recommended video:
06:06
Uniform Distribution

Frequency Distribution

A frequency distribution displays how often each value occurs within a dataset, often represented in a histogram. In the provided graph, heart rates are plotted against their frequencies, allowing for visual analysis of the data's central tendency. Observing the highest bars can help identify the mode, while the overall shape can indicate whether the median or mean might be more representative.
Recommended video:
Guided course
06:38
Intro to Frequency Distributions