Q. 1 - The Practice of Statistics for AP

Question

How can we help wood surfaces resist weathering, especially when restoring historic wooden buildings? In a study of this question, researchers prepared wooden panels and then exposed them to the weather. Here are some of the variables recorded: type of wood (yellow poplar, pine, cedar); type of water repellent (solvent-based, water-based); paint thickness (millimeters); paint color (white, gray, light blue); weathering time (months). 

Identify each variable as categorical or quantitative.

Step-by-Step Solution

Answer

The wood, paint colour and water-repellant are represented as categorical variables and weathering time and paint thickness are represented as quantitative variables.

Step 1: Categorical variables

Categorical variables are  wood, paint colour and water repellent that takes on a limited number of possible values. 

Step 2: Quantitative variables

Quantitative variables are  the paint thickness and weathering time that is measured on the numerical scale.