Question

which variable is numerical?
heating source (natural gas/electricity/oil)
type of payment method (cash/check/credit card)
apartment floor level (ground/upper/penthouse)
monthly water usage (gallons)

Explanation:

Step1: Understand variable types

Categorical variables describe a characteristic or category. Numerical variables represent a quantity that can be measured.

Step2: Analyze each variable

• Heating source (natural gas/electricity/oil) is a categorical variable as it represents different categories of heating sources.
• Type of payment method (cash/check/credit card) is a categorical variable as it represents different payment - related categories.
• Apartment floor level (ground/upper/penthouse) is a categorical variable as it represents different location - based categories.
• Monthly water usage (gallons) is a numerical variable as it represents a measurable quantity (volume of water) in gallons.

Answer:

Monthly water usage (gallons)