Troubleshoot Analysis Issues DA0-001 Practice Questions (Page 5)

Questions 21–25

1. 21foundation · easy

   While using a data analysis tool, an analyst notices that a column of numeric data is being treated as text, causing calculations to fail. Which feature of the tool should the analyst use to resolve this issue?

   • AData type conversion
   • BPivot table creation
   • CSorting
   • DFiltering
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2. 22expert · hard

   A senior analyst is troubleshooting a complex data pipeline failure that produces different error messages depending on the day. The analyst has spent several hours investigating alone without success. The errors seem to be related to data quality, but the root cause is unclear. According to best practices for problem-solving, what should the analyst do next?

   • AContinue to test different hypotheses in isolation, as bringing in others may slow down the troubleshooting process
   • BSearch online forums for the exact error messages before involving the team, as this is a more independent approach
   • CRestart the entire pipeline to see if the issue resolves itself, as this is the fastest way to clear transient errors
   • DDocument the observed error patterns and schedule a meeting with the data engineering and source system teams to brainstorm potential causes
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4. 23foundation · easy

   An analyst needs to write a script to automate the detection of duplicate records across multiple CSV files. Which tool is most appropriate for this task?

   • AA data visualization tool
   • BA programming language such as Python
   • CA database management system
   • DA spreadsheet application
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5. 24application · medium

   A data analyst is running a Python script and receives the error 'KeyError: 'customer_id''. The analyst has already checked the column names in the DataFrame and confirmed 'customer_id' exists. What is the most likely cause of this error?

   • AThe column name has leading or trailing whitespace, or the case is different (e.g., 'Customer_ID')
   • BThe Python environment is out of memory
   • CThe script is trying to access a row index instead of a column name
   • DThe DataFrame is empty
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6. 25application · medium

   An analyst is validating a dataset and wants to quickly check if there are any outliers in a continuous variable like 'customer age'. Which visualization is most appropriate for this task?

   • AA stacked bar chart
   • BA pie chart
   • CA box plot
   • DA line chart
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