Treat everyone with sincerity they will certainly appear
- Slides: 8
Treat everyone with sincerity, they will certainly appear likeable and friendly. 1
Data Analysis with SAS Topic: Descriptive Statistics By Prof Kelly Fan, Cal State Univ, East Bay 2
Two Basic Strategies to Explore Data l Begin by examining each variable by itself. Then move on to study the relationship among the variables. l Begin with a graph or graphs. Then add numerical summaries of specific aspects of the data. 3
Descriptive Statistics l Displaying data/variables with graphs ¡ for categorical (qualitative) variables: Bar plot and Pie chart ¡ for quantitative variables: Stemplot, Histogram, Boxplot and Scatterplot l Describing data/variables with numbers ¡ for categorical (qualitative) variables: l Relative Frequency (Sample Proportion) l Frequency ¡ for quantitative variables: l to measure center: Mean and Median l to measure spread: Interquartile Range (IQR) and Standard Deviation l outliers l five-number summary (boxplot) 4
Descriptive Statistics for Two Variables l 1 categorical + 1 quantitative variables ¡Summary table; bar chart; (side-by-side) boxplot l 2 categorical variables ¡Contingency table; (side-by-side) bar chart l 2 quantitative variables ¡Correlation coefficient; scatterplot 5
Descriptive Statistics for Three Variables l 1 categorical + 2 quantitative variables ¡Regression; scatterplot l 2 categorical + 1 quantitative variables ¡Summary table; bar chart 6
Observed Data: Gender M F F M M Height (inches) 68. 5 61. 2 63. 0 70. 0 68. 6 65. 1 72. 4 69. 5 Example 1 Weight (pounds) 155 99 115 205 170 125 220 188 College Sci Bsns Sci Arts Bsns Arts Sci 7
SAS Data Input l SAS: One variable per column l Example: HTWT. sas 8
