1 Treat everyone with sincerity, they will certainly appear loveable and friendly.

2 Applied Statistics Using SAS and SPSS Topic: Descriptive Statistics By Prof Kelly Fan, Cal State Univ, East Bay

3 Two Basic Strategies to Explore Data Begin by examining each variable by itself. Then move on to study the relationship among the variables. Begin with a graph or graphs. Then add numerical summaries of specific aspects of the data.

4 Descriptive Statistics Displaying data/variables with graphs  for categorical (qualitative) variables: Bar plot and Pie chart  for quantitative variables: Stemplot and Histogram Describing data/variables with numbers  for categorical (qualitative) variables: Relative Frequency (Sample Proportion) contingency table  for quantitative variables: to measure center: Mean and Median to measure spread: Interquartile Range (IQR) and Standard Deviation outliers five-number summary and boxplot scatterplot

5 Observed Data: Example 1 GenderHeight (inches) Weight (pounds) College M Sci F61.299Bsns F Bsns M Sci M Eng F Bsns M Eng M--188Sci

6 Controlled Data:Example 2 The tension bond strength of cement mortar is an important characteristic of the product. An engineer is interested in comparing the strength of a modified formulation in which polymer latex emulsions have been added during mixing to the strength of the unmodified mortar. The experimenter has collected 10 observations on strength for the modified formulation and another 10 observations for the unmodified formulation.

7 ModifiedUnmodified

8 SAS/SPSS Data Input SPSS: One variable one column in the work sheet SAS: One variable one name