Which statement about the modeling of the number of bidders is true?

Which statement about the modeling of the number of bidders is true?

• A. The number of bidders is modeled with a normal distribution.
• B. The range for bidder counts is two to four.
• C. The distribution is used to model uncertainty in bidder count.
• D. The number of bidders is modeled as a discrete uniform distribution across two to eight.

Answer: (D)

Key idea: the number of bidders is a discrete count, so it should be modeled with a discrete distribution that assigns probabilities to integer values. Choosing a discrete uniform distribution across two to eight means every possible bidder count (2, 3, 4, 5, 6, 7, 8) is equally likely. This handles uncertainty about how many bidders will participate without bias toward any particular count, and it respects the fact that bidder counts come in whole numbers. The other options don’t fit as well. A normal distribution is a continuous variable and spans many real values, which isn’t appropriate for a count of bidders. Restricting the range to two to four is too narrow and ignores plausible higher counts. While it’s true we model uncertainty in bidder count, a discrete uniform over a reasonable range best reflects a neutral, count-based uncertainty for this scenario.

Key idea: the number of bidders is a discrete count, so it should be modeled with a discrete distribution that assigns probabilities to integer values.

Choosing a discrete uniform distribution across two to eight means every possible bidder count (2, 3, 4, 5, 6, 7, 8) is equally likely. This handles uncertainty about how many bidders will participate without bias toward any particular count, and it respects the fact that bidder counts come in whole numbers.

The other options don’t fit as well. A normal distribution is a continuous variable and spans many real values, which isn’t appropriate for a count of bidders. Restricting the range to two to four is too narrow and ignores plausible higher counts. While it’s true we model uncertainty in bidder count, a discrete uniform over a reasonable range best reflects a neutral, count-based uncertainty for this scenario.