7-23 Flexible-budget preparation and analysis. Dartford Enterprises Ltd manufactures just one product line of scientific calculators for engineers. The current standard cost of one unit of the product is as follows: During last month, due to an unexpected fall in demand for the product, only 15,000 units were made and sold. The actual results for last month were as follows: 1. Prepare a static-budget-based variance analysis of last month's performance. 2. Prepare a flexible-budget-based variance analysis of last month's performance. 3. Which department manager(s) contributed the most to the success or failure of the budget during the month? Explain your