TwoWay Frequency Tables and Marginal Frequency Tables SUMMARIZE

Two-Way Frequency Tables and Marginal Frequency Tables SUMMARIZE CATEGORICAL DATA

Numerical vs. Categorical Data Numerical data are data that can be placed on a numerical scale and compared. data that are numbers. ie: height, weight, age, price, temperature, test scores, etc. All the analysis you did in the last unit was on numerical data (mean, median, IQR, outliers, standard deviation etc) Categorical Data data are data that can be grouped into categories. that aren’t numbers. ie: eye color, hair color, favorite ice cream, favorite superhero, city of birth, etc.

Data Distributions Frequency Distribution / Two-Way Frequency Table is a table that displays the frequency for categorical data by representing the number of occurrences for two variables. It’s the actual data results tally # of people in each category Marginal Frequency Distribution is a table that additionally displays the total of the frequencies of the rows or columns. It’s the actual data results including a row and column for totals

Types of Frequencies: Joint Frequency: The data within the body of a two-way table the entries in the middle cells (yellow section) Marginal the Frequency: The row total and column totals in the far right column and the bottom row (blue sections)

Another Representation You could also use this data to make a bar graph to give a visual representation of the data

Example: Data was collected from 100 men and 100 women about their favorite DC comic book superheroes: Wonder Woman, Batman, or Superman. This is categorical data because the two variables are gender (male/female) and favorite superhero (WW, BM, SM). Ideas or categories, not numbers. Here data is displayed in a frequency distribution or two-way frequency table (table with just the actual data results from survey). Here data is displayed in a marginal frequency distribution with actual data results and includes a row and column for totals) (table

Data was collected from men and women about their favorite DC comic book superheroes: Wonder Woman, Batman, or Superman. We learn some basic information from the table when it is displayed in this format. 87 Of people prefer Wonder Woman. the 87 people who prefer Wonder Woman, 62 of them were women.

Types of Distribution Recap talk with your teams to compare the two types of distributions