The uniform distribution for part cost per unit is defined over which interval?

• A. 0 to 1
• B. 100 to 180
• C. 60 to 120
• D. 80 to 100

Answer: (D)

A uniform distribution means every value within its defined interval is equally likely, and values outside that interval have zero probability. Here, the cost per unit is modeled as uniform over 80 to 100, so any cost between 80 and 100 is equally likely and costs outside that range are impossible. The constant density is 1/20 across 80 to 100. This interval matches the given bounds for the cost per unit, so it’s the correct description. Other intervals would imply different feasible ranges for the cost (for example, 0 to 1 is far too small for a unit cost, 100 to 180 shifts all values higher, and 60 to 120 extends beyond the stated limit), which is why 80 to 100 is the appropriate interval.