CHAPTER 3
Descriptive Statistics
LEARNING OBJECTIVES
The focus of Chapter 3 is the use of statistical techniques to describe data, thereby enabling you to:
- Apply various measures of central tendency—including the mean, median, and mode—to a set of ungrouped data
- Apply various measures of variability—including the range, interquartile range, mean absolute deviation, variance, and standard deviation (using the empirical rule and Chebyshev's theorem)—to a set of ungrouped data
- Compute the mean, median, mode, standard deviation, and variance of grouped data
- Describe a data distribution statistically and graphically using skewness, kurtosis, and box-and-whisker plots
- Use computer packages to compute various measures of central tendency, variation, and shape on a set of data, as well as to describe the data distribution graphically

Laundry Statistics
According to Procter & Gamble, 35 billion loads of laundry are run in the United States each year. Every second 1,100 loads are started. Statistics show that one person in the United States generates a quarter of a ton of dirty clothing each year. Americans appear to be spending more time doing laundry than they did 40 years ago. Today, the ...