Final answer:
The variable 'amount of money spent on CDs this year' is a quantitative variable because it represents a numerical measure that can be measured and expressed in numbers. The correct answer is b. The variable is quantitative because it is a numerical measure.
Step-by-step explanation:
The amount of money spent on CDs this year is an example of a quantitative variable because it represents a numerical measure of how much money has been spent. Quantitative data can be discrete or continuous, and in this case, the amount of money spent can include any value within a range, making it continuous.
It's important to distinguish that quantitative data refer to attributes that can be measured and expressed in numbers, opposed to qualitative data, which describe attributes through words or letters.
An example of qualitative data would be the genre of music on the CDs, as it would categorize them into different groups like rock, pop, or classical.
Quantitative data are always numbers and are the result of counting or measuring attributes of a population. In this case, the variable represents the amount of money spent on CDs, which can be measured in dollars.