Descriptive Statistics

• primarily used to report on populations and samples 
• speeds-up and simplifies comprehension of a group's characteristics
• sumarizing data 
• central tendency
• mean 
• median 
• mode
• mean can be affected by outliers 
• the median is unaffected by outliers, making it a better statistic 
• mode 
• the most common data point 
• it is possible to have more than one mode 
• in skewed data the mean and median lie further toward the skew 
• variation 
• range 
• the spread or the distance between the lowest and highest values of a variable 
• variance 
• a measure of the spread of the recorded values on a variable. A measure of dispersion 
• a number that at first seems complex to calculate 
• skewness 
• a normal distribution has no asymmetry