After reading this chapter, you should be able to

• Explain the purpose of descriptive statistics.
• Distinguish between inferential and descriptive statistics.
• Explain the difference between a frequency distribution and a grouped frequency distribution.
• Read and interpret bar graphs, line graphs, and scatter plots.
• Calculate the mode, median, and mean.
• List the strengths and weaknesses of the mode, median, and mean.
• Explain positive skew and negative skew.
• Explain the impact of skewness on the measures of central tendency.
• Describe and interpret the different measures of variability.
• Calculate the range, variance, and standard deviation.
• Explain percentile ranks and z scores.
• Explain how to construct and interpret a contingency table.
• Explain the difference between simple and multiple regression.
• Explain the difference between the y-intercept and the regression coefficient.