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Data Tools and Visualization Flashcards

6 cards from real DAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Data Tools and Visualization flashcards as text

  1. What is SQL and why is it essential for data analysts?

    Answer: Structured Query Language — the standard language for querying, manipulating, and managing relational databases

    SQL is the universal language for interacting with relational databases, enabling analysts to retrieve specific data (SELECT), filter (WHERE), join tables, aggregate (GROUP BY), and perform complex data manipulation.

  2. When should you use a bar chart versus a line chart?

    Answer: Bar charts for comparing categories; line charts for showing trends over time

    Bar charts effectively compare discrete categories or groups, while line charts show continuous data trends over time. Choosing the wrong chart type can misrepresent the data and mislead the audience.

  3. What is a dashboard in data analytics?

    Answer: An interactive visual display of key metrics and KPIs, providing at-a-glance monitoring of business performance

    Analytics dashboards consolidate key metrics, KPIs, and visualizations into a single interactive interface, enabling stakeholders to monitor performance, identify trends, and make data-driven decisions quickly.

  4. What is Python's role in data analytics?

    Answer: A versatile programming language with libraries (pandas, NumPy, matplotlib) for data manipulation, analysis, and visualization

    Python is widely used for data analytics through libraries like pandas (data manipulation), NumPy (numerical computing), matplotlib/seaborn (visualization), and scikit-learn (machine learning), offering flexibility beyond spreadsheet tools.

  5. What is A/B testing in data-driven decision making?

    Answer: Comparing two versions of something (webpage, email, feature) by randomly assigning users to each version and measuring outcomes

    A/B testing randomly divides users into control (A) and treatment (B) groups, each seeing a different version, to statistically determine which performs better on defined metrics, enabling evidence-based decisions.

  6. What is data storytelling?

    Answer: Combining data, visuals, and narrative to communicate analytical findings effectively to stakeholders

    Data storytelling weaves together accurate data, compelling visualizations, and a clear narrative structure to make analytical insights accessible, memorable, and actionable for non-technical audiences.