Explanation
This question is directly from the Official Tableau Desktop Specialist exam guide.
Since we are talking about the AVERAGE home values for the United States in 2016, the question is directly offering us a hint that the answer has something to do with aggregation and that too the values tell us that we're working with MEASURES.
Date part and Date values don't really make much sense given the question, and neither does geography.
Therefore, the answer naturally is "An aggregated measure".

Explanation
You can show trend lines in a visualization to highlight trends in your data.
To add trend lines to a view, both axes must contain a field that can be interpreted as a number. For example, you cannot add a trend line to a view that has the Product Category dimension, which contains strings, on the Columns shelf and the Profit measure on the Rows shelf.
However, you can add a trend line to a view of sales over time because both sales and time can be interpreted as numeric values.

Explanation
From the data pane, simply right click on the dimension, choose geographic role, and then select the appropriate role as follows:

Explanation
According to the official Tableau documentation:
Depending on the version the extract was created in, Tableau extract files can have either the .hyper or .tde file extension. Extract files are a local copy of a subset or entire data set that you can use to share data with others, when you need to work offline, and improve performance. For more information, see Extract Your Data.

Explanation
Not too tough. Follow along the steps:
* Drag Color to Filter and choose Red:
* 3) Now to display the percentage correctly, lets format it. Click on the In Stock % pill in the Row shelf, and select format:
* And your final view will look like :