a) Design a data warehouse model for an insurance company, focusing on their customers' insurance policies using the star schema. There must be at least FOUR (4) dimension tables. Use the following requirements for the model. - A policy book with the key performance indicator of the ceiling amount. The higher the amount, the more valuable is the policy - A customer may subscribe to many insurance policies - A record of the location and time the policy was made should be kept - An agent is attached to a single branch, and the insurance company have many branches - An agent can handle many customers