Final answer:
Duration and cost are not independent in estimations; they are closely interrelated. Effective estimation involves understanding how variables such as resources, task complexity, and external factors affect both duration and cost.
Step-by-step explanation:
When preparing estimations, the notion that duration and cost are independent of each other is false. In the practice of estimation, especially within the context of project management, these two variables are often intimately related. To effectively estimate project duration and costs, project managers must consider how resource allocation, the complexity of tasks, and external factors influence both the time required to complete a project and the financial resources needed. Strategies to enhance the practice of estimation include breaking down projects into smaller tasks, understanding the relationship between task complexity and resource demand, and accounting for unforeseen events.