TDA-C01 VCE Exam Download

There are different ways to create a table calculation that shows sales growth over each year, but one possible answer is:

• SUM([Sales])
• LOOKUP(SUM([Sales]), -1)
• PREVIOUS_VALUE(0)

 To calculate the sales growth over each year, you need to compare the current year’s sales with the previous year’s sales and divide the difference by the previous year’s sales. You can use the SUM, LOOKUP, and PREVIOUS_VALUE functions to achieve this. The SUM function returns the total sales for each year. The LOOKUP function returns the value of an expression in a target row, specified as a relative offset from the current row. The PREVIOUS_VALUE function returns the value of the expression in the previous row, or a specified value if there is no previous row. The formula for the table calculation is:

(SUM([Sales]) - LOOKUP(SUM([Sales]), -1)) / PREVIOUS_VALUE(0)

This formula subtracts the sales of the previous year (LOOKUP(SUM([Sales]), -1)) from the sales of the current year (SUM([Sales])) and divides the result by the sales of the previous year. If there is no previous year, the formula uses 0 as the denominator (PREVIOUS_VALUE(0)) to avoid division by zero errors.

References:

• Tableau Certified Data Analyst Exam Prep Guide, page 11, section “Creating Calculated Fields”
• Tableau Help: SUM Function
• Tableau Help: LOOKUP Function
• Tableau Help: PREVIOUS_VALUE Function

To build the scatter plot shown in the image, you need to place the Profit measure on the Rows shelf and the Sales measure on the Columns shelf. This will create a Cartesian chart with Profit as the y-axis and Sales as the x-axis. Then, you need to change the mark type to Circle on the Marks card. This will display the data points as circles that vary in size according to the Quantity measure. You can also add color or shape encoding to the marks to show additional dimensions or measures in the view. References:

• Build a Scatter Plot
• Understanding and Using Scatter Plots
• Scatter plot in Tableau

The correct order of the three actions is:

• Add the date to the Columns shelf. Add the segment and the sales to the Rows shelf.
• Aggregate the date to month and year.
• From the Analytics pane, drag Forecast to the worksheet.

The first action is to add the date to the Columns shelf and the segment and the sales to the Rows shelf. This will create a line chart that shows the daily sales by segment over time. You can use the Show Me menu to choose a line chart if it is not selected by default.

The second action is to aggregate the date to month and year. This will group the daily sales into monthly sales and show the yearly trend. You can right-click on the date field on the Columns shelf and select Month (January 2017) from the menu. You can also drag Year from the Dimensions pane to the Columns shelf before or after Month.

The third action is to drag Forecast from the Analytics pane to the worksheet. This will add a forecast that predicts future sales by segment based on historical trends. You can customize the forecast by clicking on it and using the options on the Marks card.

The other options are not relevant for this scenario. Adding a trend line would show a linear or nonlinear relationship between two measures, but not a prediction of future values. Creating a calculated field that uses the model quantile function would return a value from a statistical model based on a given quantile, but not a forecast.

References: