Which of the following is NOT a discrete random variable?

• A. The number of customers who visit a coffee shop each day.
• B. The number of defective products in a shipment of 500 items.
• C. The number of employees in a company's human resources department.
• D. The annual revenue of a technology startup (in dollars).

Answer: (D)

Verified step by step guidance

1. Understand the definition of a discrete random variable: A discrete random variable is one that can take on a countable number of distinct values. These values are often integers and can be listed out.
2. Examine each option to determine if it can be considered a discrete random variable. For example, the number of customers visiting a coffee shop each day can be counted and listed as distinct integer values.
3. Consider the number of defective products in a shipment. This is also countable and can be represented as distinct integer values, making it a discrete random variable.
4. Evaluate the number of employees in a company's human resources department. This is a countable number and can be represented as distinct integer values, qualifying it as a discrete random variable.
5. Analyze the annual revenue of a technology startup. Revenue is typically measured in continuous terms (dollars and cents) and can take on any value within a range, making it a continuous random variable rather than a discrete one.