Social security number is an example of a. a numerical variable. b. a categorical variable. c. either a numerical or a categorical variable. d. a semi-structured variable.

b.a categorical variable.

Explanation:

In numerical variables, such as rainfall measured in inches or the number of sales in a day, the numbers have a numerical meaning. But a categorical variable is a category such as gender and national origin. It can be represented as a number, like the Social security number, but the numbers won´t have a numerical value. If your SSN is bigger than mine, it doesn´t mean that you are greater or at a different level on a scale, because the numbers are used as categories, not as mathematically meaningful.    

many citizens are in danger of contracting a food-borne illness.

more people are living with chronic illnesses.

pathogens are becoming stronger and harder to defeat.

edge nuity

answer; sociological imagination;