A stock life insurance company that issues both participating and nonparticipating policies is doing business on:

A stock life insurance company that issues both participating and nonparticipating policies operates on a mixed plan. This is because a mixed plan involves a combination of both types of policies. Participating policies allow policyholders to receive dividends based on the insurer's performance, essentially sharing in the profits. In contrast, nonparticipating policies do not pay dividends and are often considered to provide guaranteed benefits without the potential for profit-sharing.

In this context, the classification of the company as a mixed plan reflects its ability to offer a diverse range of products to meet different customer needs. This approach enables the insurer to cater to a broader market by providing options for those looking for profit-sharing through participating policies as well as those who prefer the stability and predictability of nonparticipating policies.

Understanding this distinction is important for insurance professionals, as it highlights how insurers can adapt their offerings and respond to market demands, while also illustrating the fundamental differences between the participating and nonparticipating policy structures.