Graded Quiz :Introduction to Data Analytics (IBM Data Analyst Professional Certificate) Answers 2025
1. Question 1
What does a typical data wrangling workflow include?
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❌ Using mathematical techniques to identify correlations in data
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❌ Predicting probabilities
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❌ Recognizing patterns
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✅ Validating the quality of the transformed data
Explanation:
Data wrangling involves cleaning, transforming, and validating data quality before analysis.
2. Question 2
OpenRefine is an open-source tool that allows you to:
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✅ Transform data into formats like TSV, CSV, XLS, XML, JSON
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❌ Enforce data governance policies
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❌ Automatically detect schemas and anomalies
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❌ Use Microsoft Power Query add-ins
Explanation:
OpenRefine is mainly used for cleaning and transforming data across many formats.
3. Question 3
What is one step in a typical data cleaning workflow?
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❌ Building classification models
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✅ Inspecting data to detect issues and errors
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❌ Clustering data
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❌ Establishing relationships between data events
Explanation:
Data cleaning always starts with examining data to find errors, missing values, and inconsistencies.
4. Question 4
When you combine rows from multiple source tables into one table, what transformation is this?
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❌ Joins
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❌ Denormalization
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❌ Normalization
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✅ Unions
Explanation:
A UNION stacks rows from multiple tables with similar structure into a single combined result set.
5. Question 5
A value vastly different from others in a dataset is called:
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❌ Missing value
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❌ Irrelevant data
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❌ Syntax error
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✅ Outlier
Explanation:
An outlier is a value that stands far outside the normal range of the dataset.
🧾 Summary Table
| Q# | Correct Answer | Key Concept |
|---|---|---|
| 1 | Validating transformed data | Data wrangling includes quality validation |
| 2 | Transform data to many formats | OpenRefine capabilities |
| 3 | Inspecting data for errors | Data cleaning step |
| 4 | Unions | Combine rows from multiple tables |
| 5 | Outlier | Value far different from others |