What is another example of a discrete random variable?

What is another example of a discrete random variable?

• A. The number of books sold tomorrow at the Drexel bookstore
• B. The time taken to complete a test
• C. The amount of rainfall in a month
• D. The average score of students

Answer: (A)

A discrete random variable is a variable that can take on a countable number of distinct values. In the context of the question, the number of books sold tomorrow at the Drexel bookstore is a clear example of a discrete random variable because it quantifies a countable event. One can only sell whole books, so the possible outcomes are whole numbers (0, 1, 2, etc.), making this variable discrete. In contrast, the other options represent continuous random variables. The time taken to complete a test can be measured in hours, minutes, or seconds, and can take on any value within an interval, thus making it continuous. Similarly, the amount of rainfall in a month can be any measurement of depth (in inches or millimeters), which also falls into the category of continuous data. Lastly, the average score of students, derived from their individual scores, represents a continuous variable since average scores can be represented as fractions or decimals and are not limited to whole numbers. Hence, the number of books sold stands out as the only discrete variable in the options provided.

A discrete random variable is a variable that can take on a countable number of distinct values. In the context of the question, the number of books sold tomorrow at the Drexel bookstore is a clear example of a discrete random variable because it quantifies a countable event. One can only sell whole books, so the possible outcomes are whole numbers (0, 1, 2, etc.), making this variable discrete.

In contrast, the other options represent continuous random variables. The time taken to complete a test can be measured in hours, minutes, or seconds, and can take on any value within an interval, thus making it continuous. Similarly, the amount of rainfall in a month can be any measurement of depth (in inches or millimeters), which also falls into the category of continuous data. Lastly, the average score of students, derived from their individual scores, represents a continuous variable since average scores can be represented as fractions or decimals and are not limited to whole numbers. Hence, the number of books sold stands out as the only discrete variable in the options provided.