Balloons Ltd produces one product: balloons. Because of wide fluctuations in demand, the Production Department experiences significant variations in monthly production levels. The master manufacturing overhead budget for the year and actual costs incurred in July are show here. The master budget is based on 120,000 direct labour hours. In July, 11,000 labour hours were actually worked, whereas 11,250 were expected to be worked. (a) Prepare a monthly flexible overhead budget for the year ended 31 December 20XX assuming monthly production levels range from 9,000 to 12,000 direct labour hours. Use increments of 1,000 direct labour hours. (b) Conduct a variance analysis for July, comparing actual results with budget data, based on the flexible budget. (c) Explain whether costs were effectively controlled