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Ch. 5 - Normal Probability Distributions
Larson - Elementary Statistics: Picturing the World 8th Edition
Larson8th EditionElementary Statistics: Picturing the WorldISBN: 9780137493470Not the one you use?Change textbook
Chapter 5, Problem 5.1.1

Given the mean of a normal distribution, how can you find the median?

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1
Understand the properties of a normal distribution: A normal distribution is symmetric about its mean, and the mean, median, and mode are all equal in a perfectly normal distribution.
Recall the definition of the median: The median is the value that separates the data into two equal halves, with 50% of the data below it and 50% above it.
Recognize that in a normal distribution, due to its symmetry, the point that divides the data into two equal halves is the same as the mean.
Conclude that for a normal distribution, the median is equal to the mean because of the symmetry of the distribution.
To find the median, simply use the given mean value, as they are identical in a normal distribution.

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Key Concepts

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

Normal Distribution

A normal distribution is a continuous probability distribution characterized by its bell-shaped curve, defined by its mean and standard deviation. In a normal distribution, the mean, median, and mode are all equal, which means that the data is symmetrically distributed around the mean.
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Mean

The mean is the average of a set of values, calculated by summing all the values and dividing by the number of values. In the context of a normal distribution, the mean serves as the central point of the distribution, indicating where the highest concentration of data points lies.
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Median

The median is the middle value of a dataset when it is ordered from least to greatest. For a normal distribution, the median is equal to the mean, as the distribution is symmetric. This property allows one to easily determine the median if the mean is known.
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Related Practice
Textbook Question

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P1.5

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Textbook Question

Finding Probabilities In Exercises 15–18, the population mean and standard deviation are given. Find the indicated probability and determine whether the given sample mean would be considered unusual.


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