Explanation
By default, measures placed in a view are aggregated by SUM, which means that the data for that field in all of the rows is combined. Measures can also be aggregated as average, median, count, or count distinct.

Explanation
Trend lines have become popular questions in recent Tableau examinations. Follow along:
1) First drag Sales to the Rows shelf and Profit to the Columns shelf:

c
You will only see a single mark since the view is aggregated.
2) Now, break down this view by state. Drag State into Detail on the Marks shelf ( or directly to the view):

3) Finally, move to the Analytics pane, and drag Trend line to the view. When you drag it, select the Linear option!:


4) The following is our view. Hover over the trend line to see the R-squared value:

Explanation
We can drag fields from the Data pane to create the structure for your visualizations.
The Columns shelf creates the columns of a table, while the Rows shelf creates the rows of a table. You can place any number of fields on these shelves.
These FIELDS are also referred to as PILLS. See below:

Explanation
In Tableau, a story is a sequence of visualizations that work together to convey information. You can create stories to tell a data narrative, provide context, demonstrate how decisions relate to outcomes, or to simply make a compelling case.
A story is a sheet, so the methods you use to create, name, and manage worksheets and dashboards also apply to stories (for more details, see Workbooks and Sheets). At the same time, a story is also a collection of sheets, arranged in a sequence. Each individual sheet (worksheet or dashboard) in a story is called a story point.
When you share a story -for example, by publishing a workbook to Tableau Public, Tableau Server, or Tableau Online-users can interact with the story to reveal new findings or ask new questions of the data.

Explanation
Yes, it is possible to create worksheet-specific filters in Tableau.
When you add a filter to a worksheet, by default it applies to the current worksheet. Sometimes, however, you might want to apply the filter to other worksheets in the workbook.
Then, you can select specific worksheets to apply the filter to or apply it globally to all worksheets that use the same data source or related data sources.