Final answer:
The 'number of new products developed' is a KPI for the Innovation and Learning Perspective of the balanced scorecard, indicating a company's focus on growth and innovation.
Step-by-step explanation:
The "number of new products developed" would be a key performance indicator (KPI) for the Innovation and Learning Perspective of the four balanced scorecard perspectives. This perspective focuses on the internal processes of an organization that are related to innovation, continuous improvement, and growth. Tracking the number of new products developed indicates how well the company is expanding its offerings and can be a gauge of its future success due to the promotion of research and development.