Which of the following is not true of a hierarchy in an Excel Data Model? Only one hierarchy per table is allowed. For example, it wouldn't be possible to create the hierarchy Continent, Country, Region, City and the hierarchy Continent, Country, State/Province, City, Zip based on a Geography table. A hierarchy must be created in the Power Pivot window. A hierarchy is often aided by DAX's RELATED function so that fields from related tables can be brought into a single table and used in bullding the hierarchy. A hierarchy's main use is to allow users to drill down through the hierarchy in a pivot table.

To determine which statement is not true regarding hierarchies in an Excel Data Model, let's analyze each statement: 1. **Only one hierarchy per table is allowed. For example, it wouldn't be possible to create the hierarchy Continent, Country, Region, City and the hierarchy Continent, Country, State/Province, City, Zip based on a Geography table.** - This statement is **not true**. In Excel's Data Model, you can create multiple hierarchies within the same table. Therefore, you can have different hierarchies based on the same set of data. 2. **A hierarchy must be created in the Power Pivot window.** - This statement is **true**. Hierarchies are created in the Power Pivot window, where you can manage your data model. 3. **A hierarchy is often aided by DAX's RELATED function so that fields from related tables can be brought into a single table and used in building the hierarchy.** - This statement is **true**. The RELATED function in DAX allows you to pull in data from related tables, which can be useful when building hierarchies. 4. **A hierarchy's main use is to allow users to drill down through the hierarchy in a pivot table.** - This statement is **true**. The primary purpose of a hierarchy in a pivot table is to enable users to drill down through different levels of data. Based on this analysis, the statement that is **not true** is the first one: "Only one hierarchy per table is allowed."