Final answer:
To understand Walmart's culture, Yakov listens to the stories managers tell in the cafeteria to observe the shared beliefs and values.
Step-by-step explanation:
Yakov determined Walmart's culture by listening to the stories that managers tell every day in the cafeteria. These stories are a form of narratives and they are used to understand and observe the shared beliefs, values, and practices that make up the company's culture.