LECTURE: AL MUIZZUDDIN F., SE., ME. Nilai Sentral

 In previous chapter, you began your study of descriptive statistics. There you learned how to organize data into tables and summarize data with graphs.  Another method of summarizing data is to compute numbers, such as averages and percentiles, that describe the data set. Numbers that are used to describe data sets are called descriptive measures. In this chapter, we continue our discussion of descriptive statistics by examining some of the most commonly used descriptive measures. 2

... descriptive measures that indicate the center, or most typical value, in a data set.  Descriptive measures that indicate where the center or most typical value of a data set lies are called measures of central tendency or, more simply, measures of center. Measures of center are often called averages. 3

4 Measure of center Mean Ungrouped data Grouped data Median Ungrouped data Grouped data Mode Ungrouped data Grouped data

 The most commonly used measure of center is the mean. When people speak of taking an average, they are most often referring to the mean. 5

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 Although the mean, the median, and the mode each describe a typical entry of a data set, there are advantages and disadvantages of using each. The mean is a reliable measure because it takes into account every entry of a data set. However, the mean can be greatly affected when the data set contains outliers. 13

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16 Find the mean, median, and mode of each data set.

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18 Find the mean, median, and mode.

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