DA0-002 Practice Test 45 — 15 Questions

Question 1

An analyst wants to show the trend of monthly sales over the past two years. Which chart type is most appropriate?

Accepted Answer

Line chart. A line chart is best for showing trends over time.

Answer

Pie chart

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Bar chart

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Scatter plot

Question 2

Which chart type is best for displaying the distribution of a continuous variable, such as the age distribution of customers?

Accepted Answer

Histogram. A histogram is the correct choice because it groups continuous data (like age) into bins along the x-axis and displays the frequency of observations within each bin as bars, making the distribution shape immediately visible. This directly addresses the need to show how customer ages are spread across the range, which is the definition of a distribution for a continuous variable.

Answer

Box plot

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Line chart

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Pie chart

Question 3

A dashboard uses a heatmap to show sales density by hour and day of week. Users report that the color scale is confusing because some low values appear similar to high values. Which design change improves clarity?

Accepted Answer

Switch to a diverging color scale. Using a diverging color scale with a neutral midpoint improves differentiation between low, medium, and high values. A sequential scale may still cause confusion. Increasing color steps or using a single hue does not address the issue.

Answer

Use a sequential color scale with more contrast

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Increase the number of color steps

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Change to a single hue gradient

Question 4

In Looker Studio, a data analyst has two data sources: one with customer IDs and transactions, and another with customer demographics. They need to create a chart that includes fields from both sources. Which feature should they use?

Accepted Answer

Data blending. Data blending in Looker Studio allows you to combine data from two or more separate data sources based on a common key (e.g., customer ID). This enables you to create a chart that uses fields from both the transactions source and the demographics source without needing to merge the data at the database level. Without blending, a single chart can only reference fields from one data source at a time.

Answer

Calculated fields

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Community connectors

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Dashboard filters

Question 5

A data analyst is creating a report to compare the performance of different sales regions. The report will be used by regional managers to identify areas needing improvement. Which of the following visualization techniques would be most effective?

Accepted Answer

A bar chart comparing each region's sales. A bar chart is most effective because it allows direct, side-by-side comparison of discrete categories (sales regions) using a common baseline, making it easy for regional managers to quickly identify which regions are underperforming. The vertical bars encode exact values with high perceptual accuracy, supporting the report's goal of highlighting areas needing improvement.

Answer

A line chart showing overall company sales

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A pie chart showing each region's contribution

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A scatter plot of sales vs. expenses

Question 6

A data analyst is evaluating the quality of a customer database. Which THREE of the following are dimensions of data quality?

Accepted Answer

Completeness. Accuracy, completeness, and timeliness are standard data quality dimensions.

Answer

Correlation

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Variance

Question 7

During a data mining project, an analyst discovers that a significant number of records have a negative value for the age field. What is the most appropriate first step?

Accepted Answer

Investigate the source system for data entry errors.. The first step in handling anomalous data like negative ages is to investigate the source system for data entry errors. This aligns with the data mining process, where understanding the root cause of data quality issues is critical before applying any imputation or removal techniques. Without investigation, you risk masking systemic problems that could affect all records.

Answer

Impute using regression.

Answer

Replace negative age with the mean age.

Answer

Remove all records with negative age.

Question 8

A marketing team uses K-means clustering to segment customers based on purchase history. To determine the optimal number of clusters, they plot the within-cluster sum of squares (WCSS) against k and look for an elbow. What is the purpose of this method?

Accepted Answer

To find the point where the rate of decrease in WCSS slows down. The elbow method helps choose k where adding more clusters yields diminishing returns in reducing variance.

Answer

To identify the value of k that minimizes WCSS

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To determine the initial centroids for the algorithm

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To ensure all clusters have equal size

Question 9

An organization is acquiring data from an external vendor. The vendor provides a flat file with inconsistent delimiters and missing values. Which step should be performed first in data acquisition?

Accepted Answer

Data profiling. Data profiling is the first step because it examines the data to understand its structure, quality, and issues (like inconsistent delimiters and missing values) before any further processing. Option A (Data integration) is wrong because integration combines data from multiple sources and should follow profiling. Option C (Data transformation) is wrong because transforming data requires first understanding its current state through profiling. Option D (Data cleansing) is wrong because cleansing is performed after profiling identifies the issues.

Answer

Data integration

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Data transformation

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Data cleansing

Question 10

Match each data governance role to its responsibility.

Accepted Answer

Data Steward: Responsible for ensuring data quality, defining data standards, and managing metadata.. Data Stewards focus on quality and metadata, Data Owners have accountability and access decisions, Data Custodians handle technical security, and Data Governors manage the governance program. Common confusions include mixing Steward with Custodian or Owner.

Answer

Data Steward: Implements technical security controls.

Answer

Data Owner: Ensures data quality and manages metadata.

Question 11

Match each data sampling method to its description.

Accepted Answer

Simple Random Sampling: Every member of the population has an equal chance of being selected.. In matching, ensure you distinguish between methods: simple random gives equal chance; stratified divides by characteristic; cluster divides into groups and picks whole groups; systematic uses a fixed interval.

Answer

Simple Random Sampling: Population is divided into clusters, and entire clusters are randomly selected.

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Stratified Sampling: Every kth member is selected from a list after a random start.

Question 12

In Power BI, an analyst wants to create a measure that calculates the total sales for the current year up to the latest date in the data. Which DAX function should be used?

Accepted Answer

TOTALYTD. TOTALYTD is a time intelligence function that sums values for the year up to the last date in the filter context (or specified end date).

Answer

SAMEPERIODLASTYEAR

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CALCULATE

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SUMX

Question 13

Which data quality dimension is violated if a customer record has a missing phone number?

Accepted Answer

Completeness. Completeness refers to the extent to which data is not missing.

Answer

Consistency

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Accuracy

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Validity

Question 14

An analyst compares average sales across three different store locations using a statistical test. Which test is most appropriate?

Accepted Answer

ANOVA. ANOVA compares means across three or more groups.

Answer

t-test

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Correlation analysis

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Chi-square test

Question 15

A data analyst calculates the mean, median, and mode of a dataset. Which measure of central tendency is most affected by extreme outliers?

Accepted Answer

Mean. The mean is sensitive to extreme values because it includes all data points in its calculation, whereas median and mode are more robust.

Answer

Range

Answer

Median

Answer

Mode