Pass DA0-001 Exam Guide

The median is recognized as the most appropriate measure of central tendency when outliers have been removed from a dataset. This is because the median is less influenced by extreme values compared to the mean. When outliers are present, they can significantly skew the mean, making it an unreliable measure of central tendency. The median, on the other hand, is the middle value of a dataset when ordered from least to greatest and remains unaffected by the extremes. Therefore, it provides a better representation of the central location of the data after outliers have been excluded.

Explanation

Power BI is a collection of software services, apps, and connectors that work together to turn your unrelated sources of data into coherent, visually immersive, and interactive insights. Your data may be an Excel spreadsheet or a collection of cloud-based and on-premises hybrid data warehouses.

Dashboards are visual tools that provide insights into various aspects of business operations. The type of dashboard developed depends on the intended audience and the nature of information to be conveyed.

Referencing Dashboard: This term is not standard in the context of dashboard types and doesn't correspond to a recognized category.

Strategic Dashboard: Designed for senior management, strategic dashboards provide a high-level overview of key performance indicators (KPIs) aligned with the organization's long-term goals. They focus on overall performance and strategic objectives, rather than detailed operational issues.

Operational Dashboard: These dashboards monitor the real-time operations of an organization. They are used to track immediate metrics and processes, allowing teams to respond quickly to issues as they arise. In the context of data pipelines, an operational dashboard would display the current status, including any failures, enabling prompt action to resolve issues.

Technical Dashboard: While this could pertain to dashboards focused on technical metrics, it's not a standard term. Operational dashboards often encompass technical aspects, especially concerning system operations and processes.

Given the need to provide information about failed data pipelines, an Operational Dashboard is most appropriate. It offers real-time monitoring and alerts for immediate issues within data processes, enabling swift identification and resolution of failures.

If a single data set was split into two files, both files typically:

Have the same columns/structure

Contain different rows (e.g., File 1 has rows 1–10,000; File 2 has rows 10,001–20,000)

The correct way to restore the original data set is to stack the rows from one file underneath the rows from the other. This operation is called:

Appending (or “union” in SQL terms):

You keep the same schema (same columns)

You increase the number of rows

Other options:

Merging usually joins based on a key column (like customer_id) to bring in additional columns.

Blending often refers to combining data from different sources on related keys, especially in BI tools.

Aggregating reduces detail (e.g., summing or grouping), which is the opposite of what we want here.

Since we simply want to rebuild the full data set from two vertical slices, the correct technique is Append (B).

CompTIA Data+ Reference (concept alignment):

CompTIA Data+ Official Exam Objectives – Domain on Data Mining / Data Preparation (combining datasets through appending vs merging).

CompTIA Data+ Official Study Guide – discussion of data append/union vs merge/join when preparing data.