Perform variance analysis for Apple's R&D and production costs.

Cost Components	Budgeted Costs ($)	Actual Costs ($)
R&D Costs	800,000,000	850,000,000
Production Costs	1,200,000,000	1,250,000,000

Requirements:

Compare actual costs to budgeted costs for different product categories.

Calculate and interpret material, labor, and overhead variances.

Identify causes of significant variances and suggest corrective actions.

Recommend strategies to improve budget accuracy and cost control.