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Statistical Analysis with R Essentials For Dummies
book

Statistical Analysis with R Essentials For Dummies

by Joseph Schmuller
April 2024
Beginner content levelBeginner
192 pages
3h 18m
English
For Dummies
Content preview from Statistical Analysis with R Essentials For Dummies

Chapter 5

Deviating from the Average

IN THIS CHAPTER

Bullet Finding out what variation is all about

Bullet Working with variance and standard deviation

Bullet Exploring R functions that calculate variation

Calculating the mean is a great way to summarize a set of numbers, but the mean might mislead you. How? By not giving you all the information you typically need. If you rely only on the mean, you might miss something important about the set of numbers.

To avoid missing important information, another type of statistic is necessary — a statistic that measures variation. Think of variation as a kind of average of how much each number in a group of numbers differs from the group mean. Several statistics are available for measuring variation. They all work the same way: The larger the value of the statistic, the more the numbers differ from their mean. The smaller the value, the less they differ.

Measuring Variation

Suppose you measure the heights of a group of children and you find that their heights (in inches) are

48, 48, 48, 48, and 48

Then you measure another group and find that their heights are

50, 47, 52, 46, and 45

If you calculate the mean of each group, you'll find they're the same ...

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Publisher Resources

ISBN: 9781394263424Purchase Link