1.4 Representing a Categorical Variable with Graphs

• Nominal variables are categorical variables with no inherent order
• Ordinal variables are categorical variables with a natural order
• Give an example of a dichotomous variable.

  Gender (male, female)
• Match the type of variable with its characteristic in a bar chart:

  Nominal Variable ↔️ Frequency of unordered categories

  Ordinal Variable ↔️ Frequency of ordered categories
• Match the type of categorical variable with its characteristic:

  Nominal ↔️ No natural order

  Ordinal ↔️ Categories have order

  Dichotomous ↔️ Only two categories
• Give an example of a nominal variable.

  Colors (red, blue, green)
• Give an example of an ordinal variable.

  Satisfaction ratings
• Dichotomous variables have only two categories.


  True
• For ordinal variables in a bar chart, the order of bars must reflect the natural order of categories.


  True
• Key differences among categorical variables lie in the presence of natural order
• A pie chart represents the percentage distribution of each category
• What does a frequency table list for a categorical variable?

  Categories and frequencies
• Frequency tables are complex to understand and interpret.

  False
• A frequency table lists each category of a categorical variable along with its frequency
• Frequency tables are suitable for numerical data.

  False
• The cumulative line in a Pareto chart helps visualize the 80/20 rule
• Match the category with its frequency in the sample Pareto chart:

  Defects ↔️ 60

  Late Deliveries ↔️ 30

  Customer Complaints ↔️ 15

  Billing Errors ↔️ 5
• Pareto charts show the cumulative percentage
• Match the type of categorical variable with its example:

  Nominal ↔️ Colors (red, blue, green)

  Ordinal ↔️ Education levels

  Dichotomous ↔️ Gender (male, female)
• Dichotomous variables have only two categories
• Dichotomous variables have only two categories.

  True
• For nominal variables, the bars in a bar chart can be arranged in any order
• Pie charts are well-suited for nominal variables because they show the distribution of categories without inherent order
• A key advantage of a frequency table is that it is easy to understand and interpret
• What does the cumulative percentage line in a Pareto chart show?

  Cumulative impact
• Pie charts are best used for showing proportions of a whole
• What is a categorical variable?

  Variable with distinct categories
• Nominal variables lack a specific order.


  True
• Dichotomous variables are categorical variables with only two categories
• What do bar charts show for categorical variables?

  Frequency or percentage
• How does a categorical variable classify data?

  Into distinct categories
• What is the purpose of bar charts in visualizing categorical variables?

  Display frequency or percentage
• Which type of categorical variable is well-suited for pie charts because it lacks inherent order?

  Nominal
• Frequency tables are easy to understand and interpret
• Frequency tables are used to summarize and organize data
• Frequency tables do not display continuous or numerical data
• Steps to construct a frequency table:

  1️⃣ List all the distinct categories of the variable

  2️⃣ Count the number of occurrences for each category

  3️⃣ Tabulate the results with categories and their frequencies
• What does a Pareto chart help identify?

  The vital few
• What is one key characteristic of a Pareto chart compared to a regular bar chart?

  Categories are ordered by frequency
• Pareto charts facilitate prioritization