Final answer:
The business problem is a consistent decline in sales revenue over several quarters, despite ongoing promotions and increased advertising, suggesting ineffective marketing strategies or other underlying issues.
Step-by-step explanation:
The business problem stated in the provided historical data is a consistent decline in sales revenue over the past several quarters, despite ongoing promotions and increased advertising expenses. This situation may indicate that the promotional strategies and advertising campaigns are not effectively stimulating customer purchases or that there might be an issue with the product mix, pricing strategy, or market changes that are not being addressed. To diagnose the problem accurately, further analysis would be necessary, such as understanding customer behavior, market trends, price sensitivity, and the effectiveness of promotional activities.