DA0-002 Practice Exam 60 — 20 Questions

Question 1

A data analyst needs to identify duplicate customer records. Which TWO methods are commonly used? (Select two.)

Accepted Answer

Fuzzy matching using Levenshtein distance. Fuzzy matching using Levenshtein distance (Option A) is correct because it measures the edit distance between two strings, allowing identification of duplicates even when there are minor typographical differences, such as 'Jon Smith' vs. 'John Smith'. This is essential for deduplicating customer records where names, addresses, or other fields may have slight variations without being exact matches.

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Visual inspection of random sample

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Using a hash function on primary key

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Exact match on all fields

Question 2

Which chart type is best for showing the distribution of a continuous variable, such as customer ages?

Accepted Answer

Histogram. A histogram is the correct choice because it groups continuous data (like customer ages) into bins along a continuous x-axis, displaying the frequency distribution through bar heights. This directly shows the shape, spread, and central tendency of the variable, which is the core requirement for visualizing a continuous distribution.

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Bar chart

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Pie chart

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Box plot

Question 3

In Looker Studio, what is the difference between dimensions and metrics?

Accepted Answer

Dimensions are categorical; metrics are numerical. In Looker Studio, dimensions are fields that contain categorical data (e.g., text, dates, or geographic names) used to group and segment data, while metrics are numerical fields (e.g., counts, sums, averages) that can be aggregated. Option D is correct because this distinction is fundamental to how Looker Studio processes and visualizes data: dimensions define the rows or categories in a chart, and metrics provide the quantitative values to be measured.

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Dimensions are used for aggregation; metrics are for grouping

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Dimensions are numerical; metrics are categorical

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Both can be categorical or numerical

Question 4

A data team needs to extract data from a legacy system that only supports flat file exports. Which data acquisition method is most appropriate?

Accepted Answer

File transfer via SFTP. The legacy system only supports flat file exports, meaning it cannot provide direct database or API access. SFTP (SSH File Transfer Protocol) is the most appropriate method because it securely transfers flat files over a network, aligning with the system's export capabilities while ensuring data integrity and encryption during transit.

Answer

Database replication

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API call

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Web scraping

Question 5

A data analyst wants to compare the revenue across five different product categories. Which chart type is best suited?

Accepted Answer

Bar chart. Bar charts are ideal for comparing categories because they display discrete values side by side.

Answer

Scatter plot

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Pie chart

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Line chart

Question 6

A data analyst notices that a line chart showing monthly sales over the past two years has a steep drop in one month. Upon investigation, the analyst discovers that a new sales region was added mid-month and the data was not normalized. Which of the following best practices should the analyst apply to communicate this insight accurately?

Accepted Answer

Normalize the sales data by region and explain the data anomaly in the report.. The core issue is that the sales data is not normalized by region, causing a misleading drop when a new region was added mid-month. By normalizing the data (e.g., calculating per-region averages or percentages) and explicitly noting the anomaly in the report, the analyst ensures accurate communication of insights. This aligns with the DA0-001 domain of Communicating Data Insights, where transparency and data integrity are paramount.

Answer

Remove the month with the drop from the report.

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Use a bar chart instead to show the data.

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Present the data as-is and let stakeholders interpret the drop.

Question 7

A data analyst needs to create a recursive CTE to traverse a hierarchical employee-manager table. Which of the following is a key requirement for a recursive CTE?

Accepted Answer

The recursive CTE must have at least one anchor member that does not reference the CTE. A recursive CTE must have an anchor member (non-recursive) and a recursive member that references the CTE name, connected by UNION ALL.

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The CTE must include a WHERE clause in the recursive member

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The CTE must use the RECURSIVE keyword in the WITH clause

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The recursive member must use UNION instead of UNION ALL

Question 8

A data analyst discovers that a dataset contains multiple records for the same customer with different spellings (e.g., 'Jon' vs 'John'). Which data preparation step should be applied first?

Accepted Answer

Standardize text fields using a lookup table.. The first step when dealing with inconsistent text values (like 'Jon' vs 'John') is to standardize the data using a lookup table or reference mapping. This ensures that all variations are normalized to a canonical form before any merging or deduplication is attempted, preventing data loss and preserving referential integrity.

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Merge all records into one per customer.

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Remove duplicates based on exact match.

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Flag records for manual review.

Question 9

Refer to the exhibit. A data analyst is unable to access the dataset during weekends. Based on the policy, what is the most likely reason?

Accepted Answer

The condition restricts access to business hours only. The policy explicitly includes a condition that restricts access to business hours only (e.g., Monday–Friday, 9 AM–5 PM). Since the analyst is attempting to access the dataset during a weekend, the condition denies access regardless of the analyst's role or network location. This is a common attribute-based access control (ABAC) rule where time-based conditions are evaluated before granting permissions.

Answer

The analyst's role is not in the list

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The policy is misconfigured

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The access condition requires being on the internal network

Question 10

Which TWO are best practices for designing effective dashboards? (Select exactly two.)

Accepted Answer

Use a single page to avoid scrolling.. Options D and E are correct. A single-page dashboard (D) allows users to see key information at a glance without scrolling, improving efficiency. A consistent color scheme (E) reduces cognitive load and makes the dashboard easier to interpret. Option A (3D charts) is discouraged because 3D effects can distort data perception and add visual clutter. Option B (pie charts) can be used for parts of a whole, but it is not a universal best practice; they become hard to compare with many categories. Option C (including every metric) leads to information overload and reduces the dashboard's effectiveness.

Answer

Use 3D charts for visual appeal.

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Use pie charts for comparing parts of a whole.

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Include every possible metric to provide completeness.

Question 11

A data analyst is using SQL to extract data. The analyst wants to retrieve all records from a table named 'sales' where the 'amount' column is greater than 100. Which SQL clause should be used?

Accepted Answer

WHERE. The WHERE clause in SQL is used to filter records based on a specified condition, such as 'amount > 100'. It is applied directly to the rows in the 'sales' table before any grouping or ordering, making it the correct choice for retrieving only records where the amount exceeds 100.

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ORDER BY

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GROUP BY

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HAVING

Question 12

Which type of chart is most suitable for showing the distribution of a single continuous variable?

Accepted Answer

Histogram. A histogram is the most suitable chart for showing the distribution of a single continuous variable because it groups the data into bins (intervals) along the x-axis and displays the frequency or count of observations within each bin on the y-axis. This allows you to see the shape, spread, and central tendency of the data, such as whether it is normally distributed, skewed, or has multiple modes. For a single continuous variable, a histogram directly visualizes the probability density or frequency distribution, which is its primary purpose in data analysis.

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Line chart

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Scatter plot

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Bar chart

Question 13

A dashboard designer needs to ensure that color choices are accessible to users with color vision deficiencies. Which practice should be followed?

Accepted Answer

Combine color with patterns or labels to convey information. Combining color with patterns or labels ensures that information is conveyed even to users with color vision deficiencies. Option A is incorrect as rainbow palettes rely solely on hue differentiation, which is problematic for color-blind users. Option B is incorrect because converting to grayscale loses the emphasis that color can provide for all users. Option C is incorrect because red-green color schemes are particularly difficult for those with red-green color blindness (the most common type).

Answer

Use a rainbow color palette to maximize differentiation

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Convert all charts to grayscale

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Use red and green to indicate positive and negative values

Question 14

A data analyst needs to visualize sales per capita across U.S. states. States with small populations but high sales (e.g., Delaware) appear too prominent on a choropleth map. Which technique best addresses this issue?

Accepted Answer

Use a choropleth map with rates instead of raw sales. A choropleth map using rates (sales per capita) normalizes for population, preventing small-population states with high sales from appearing overly prominent. Options A, C, and D do not properly normalize the data: A changes chart type but does not normalize, C uses raw sales, and D applies a log scale which distorts the relationship without normalizing for population.

Answer

Switch to a bar chart sorted by sales

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Use a bubble chart with size proportional to sales

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Apply a log scale to the color gradient

Question 15

A dashboard needs to show sales trends for each of five regions over the past year. The intended audience wants to compare trends easily. Which chart type is best?

Accepted Answer

Line chart with multiple lines. A line chart with multiple lines allows the audience to easily compare trends across the five regions over time. Each region can be represented by a separate line, making it simple to see upward or downward trends and compare them side by side. In contrast, a pie chart shows parts of a whole and is not suitable for trend comparison; a stacked bar chart emphasizes composition rather than trends; and an area chart is similar to a line chart but can obscure overlapping trends due to stacking.

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Pie chart

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Stacked bar chart

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Area chart

Question 16

A table named Orders has columns OrderID, CustomerID, OrderDate, and TotalAmount. Which column should be the primary key to uniquely identify each order?

Accepted Answer

OrderID. The OrderID column is the correct choice for the primary key because it contains unique values for each order, ensuring that each row can be uniquely identified. A primary key must be unique, non-null, and stable; OrderID satisfies all these requirements, whereas the other columns do not guarantee uniqueness or are subject to change.

Answer

OrderDate

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TotalAmount

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CustomerID

Question 17

A data scientist has a dataset with 50 variables and wants to identify clusters of similar observations. Which visualization technique is most suitable for reducing dimensionality to 2D while preserving cluster structure?

Accepted Answer

Scatter plot of first two principal components. PCA reduces the dimensionality of a 50-variable dataset to two principal components while preserving the variance, making clusters visible in a scatter plot. Parallel coordinates (C) is useful for visualizing high-dimensional data but does not inherently preserve cluster structure. Heatmap of correlations (A) shows relationships between variables, not observations. Scatter matrix (B) becomes impractical with 50 variables due to the number of plots, and it does not reduce dimensionality.

Answer

Heatmap of correlations

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Scatter matrix (pairplot)

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Parallel coordinates plot

Question 18

Refer to the exhibit. A data analyst wants to grant read access to an entire cloud storage bucket named 'data-lake'. Which of the following best describes what this policy does?

Accepted Answer

Allows read access to all objects in the data-lake bucket. This policy grants read access to all objects within the 'data-lake' bucket. In cloud storage, a bucket-level policy that allows the 'GetObject' action without a condition restricting the resource to a specific prefix or folder effectively permits reading every object in the bucket. Option D correctly identifies this behavior.

Answer

Allows both read and write access to the bucket

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Allows only specific users to read objects

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Allows read access to a specific folder within the bucket

Question 19

A data audit reveals that some numbers in the "Revenue" column were manually entered from PDF invoices. This introduces potential errors. Which data concept is being addressed?

Accepted Answer

Data quality. The scenario describes a data audit that identifies potential errors from manual data entry from PDF invoices. This directly relates to data quality, which assesses aspects like accuracy, completeness, and consistency. The audit is highlighting a quality concern (potential errors), not lineage tracking. Data lineage focuses on the origin and transformation of data, but the primary issue here is the risk of inaccuracies, making data quality the correct concept.

Answer

Data lineage

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Data security

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Data governance

Question 20

Which TWO of the following are examples of data transformation? (Choose TWO.)

Accepted Answer

Normalizing data to eliminate redundancy. Data normalization is a transformation process that reorganizes data to reduce redundancy and improve integrity, typically by decomposing tables into smaller, related tables (e.g., achieving 3NF in relational databases). This changes the structure and representation of the data, which is a core example of data transformation.

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Creating a backup of the database

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Generating summary statistics

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Removing duplicate records