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    Question

    A data analyst is working with a dataset containing

    missing values, duplicate entries, and inconsistent formats. What is the most important step in ensuring this dataset is ready for analysis?
    A Visualizing the data to identify key trends. Correct Answer Incorrect Answer
    B Cleaning the data by handling missing values, duplicates, and inconsistencies. Correct Answer Incorrect Answer
    C Building predictive models to compensate for missing data. Correct Answer Incorrect Answer
    D Aggregating the data to create a summarized dataset. Correct Answer Incorrect Answer
    E Generating automated reports from the raw dataset. Correct Answer Incorrect Answer

    Solution

    Explanation: Data cleaning is a crucial step in the data wrangling process, ensuring that datasets are accurate, reliable, and analysis-ready. It involves addressing missing values (e.g., imputing or removing), eliminating duplicates that skew metrics, and standardizing formats for consistency. These steps improve the dataset's integrity and prevent analytical errors. For example, ignoring missing data might lead to biased results, while duplicates can overstate performance metrics like sales volume. Cleaning ensures the dataset reflects reality, forming a robust foundation for valid analysis and decision-making. Option A: Visualizing data is useful for understanding trends but does not resolve issues like missing values or inconsistencies in the dataset. Option C: Building predictive models on unclean data can lead to inaccurate predictions, as the underlying dataset might contain errors. Option D: Aggregating data might simplify analysis but does not address core issues such as missing values or inconsistencies. Option E: Generating reports without cleaning the dataset can lead to incorrect or misleading interpretations of the data.

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