Final answer:
The flexible-budget formula for Young Corporation is Y = $4.50AH + $720,000, where Y represents total cost and AH represents activity hours. The formula calculates the total cost based on the variable cost per hour of activity and the fixed costs.
Step-by-step explanation:
The flexible-budget formula for Young Corporation is Y = $4.50AH + $720,000. This formula represents the total cost (Y) as a function of the activity hours (AH). The $4.50 represents the variable cost per hour of activity, and the $720,000 represents the fixed costs. By plugging in the different activity hours (30,000, 40,000, and 50,000) into the formula, you can calculate the total cost for each scenario.