STA 215 Chapter Notes - Chapter 1,2: Amazon Standard Identification Number, Marginal Distribution, Bar Chart
Document Summary
Data- any collection of numbers, characters, images, or other items that provide information about something. Rows of a data table correspond to individual cases about whom (or about which) we record some characteristics. Experimental units- animals, plants, websites, other inanimate subjects. Cases are often samples (representatives) from larger populations (generalization) Categorical/qualitative/nominal variables- name categories, tell us what group or category each individual belongs to: ex) male or female, pierced or not, can also be numerals. Quantitative variables- contain measured numerical values with measurement units; record an amount or degree of something; have mathematical relationships. Some variables with numeric values can be treated as either: ex) age in the categories child, teen, adult, or senior. All has to do with what we want to ask about the data (the why ) Identiier variable- has exactly as many values as cases: ex) id numbers (all individuals receive unique value, as opposed to sex (m or f)
