Explanation:
The correct order of the three actions is:
From the connections pane, connect to both data sources
Join both datasets and select the join type
Specify Employee Name as the join key
The first action is to connect to both data sources from the connections pane in Tableau Prep. The connections pane is where you can access and add data sources to your flow. You can connect to various types of data sources, such as Excel, SQL Server, or Tableau Server. In this case, you want to connect to an Excel worksheet and a SQL Server table.
The second action is to join both datasets and select the join type. A join is a way of combining data from two or more tables based on a common field. You can join datasets by dragging one table to the canvas and dropping it on top of another table. This will create a join step in your flow. You can select the join type from the drop-down list on the join step. The join type determines which rows are returned from the tables.
The third action is to specify Employee Name as the join key. A join key is a field that is used to match rows from different tables. You can specify the join key by clicking on the field name in each table and dragging it to the center of the join step. This will create a join clause that shows the field name and the operator. In this case, you want to use Employee Name as the join key, because it is a common field between the two datasets.
The other options are not relevant for this scenario. Specifying Department and Team Size as a join condition will not work, because they are not common fields between the two datasets. Opening both data sources in Tableau Desktop will not help you join them in Tableau Prep. Adding a step to aggregate the data in the SQL Server table will not affect the join, but it may change the level of detail of your data. References:
https://help.tableau.com/current/prep/en-us/prep_connect.htm
https://help.tableau.com/current/prep/en-us/prep_join.htm
https://help.tableau.com/current/prep/en-us/prep_join_types.htm

The question presents a scenario where a geographic map visualization in Tableau needs to be transformed from a series of discrete circles representing data points to a density map visualization. The density map shows concentrations of data points with a gradient of color, where denser areas are indicated by a darker color.
Here's the explanation for each option:
A). Change the mark type to Density: This is the correct answer because changing the mark type to 'Density' in Tableau creates a density map, which displays the concentration of data points with a color gradient. This is exactly what is needed to achieve the visual effect shown in the second image, where regions with a higher concentration of data points are represented by darker shades.
B). Drag Location to Size on the Marks card: This option would adjust the size of the marks based on the number of locations, which is not relevant to creating a density map. It would result in varying sizes of circles, not a continuous gradient.
C). Change the mark type to Map: The visualization is already using a map. This option would not change the visualization to the desired density map.
D). Drag Population to Size on the Marks card: This would change the size of the circles based on the population values, making some circles larger and others smaller. This is not how a density map is created, which uses color intensity rather than size to show concentration.
E). Change the opacity to 75%: Changing the opacity would affect the transparency of the marks on the map but would not transform the visualization into a density map.
To achieve the visualization shown in the second image, the mark type must be changed to 'Density,' which will produce a heat map-like effect where the color intensity represents the concentration of data points.
Therefore, the correct answer is A. Change the mark type to Density.
To create a density map from a scatter plot of data points, you would change the mark type to Density. This mark type allows you to visualize the concentration of data points in an area, which can be useful for identifying clusters or patterns in geospatial data.

To show the corresponding region when users hover their mouse over any of the bars, you need to drag Region to Tooltip on the Marks card. This will add Region as a field in the tooltip text that appears when users hover over a mark. You can also customize the tooltip text by editing it in the Tooltip dialog box. Reference: https://help.tableau.com/current/pro/desktop/en-us/buildmanual_shelves.htm https://help.tableau.com/current/pro/desktop/en-us/formatting_tooltips.htm

To create a map visualization that shows the concentration of data points in different locations, you need to change the mark type to Density. This will create a heatmap that uses color and size to indicate the density of the data points. You can also adjust the intensity and transparency of the density marks to suit your needs. References: The information is based on the following sources:
* Create Heatmaps that Show Trends or Density in Tableau
* Build a Simple Map - Tableau