DA0-001 Visualizing Data Practice Test 2 — 15 Questions

Question 1

A data analyst is creating a dashboard for a retail company. The dashboard should provide insights into sales performance across multiple dimensions. Which TWO chart types are best suited for showing the contribution of each product category to total sales?

Accepted Answer

Pie chart. A pie chart is ideal for showing the contribution of each product category to total sales because it visually represents parts of a whole, making it easy to compare proportions at a glance. The stacked bar chart also effectively shows category contributions within a total, allowing for both absolute and relative comparisons across different time periods or segments. Both chart types directly address the need to visualize proportional breakdowns of a single aggregate metric.

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Scatter plot

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Histogram

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Line chart

Question 2

You are a data analyst for a logistics company. The company has a fleet of delivery trucks and tracks performance metrics including delivery time, fuel consumption, and distance traveled. Management wants a dashboard to monitor driver efficiency and identify underperforming drivers. You have access to a dataset with columns: DriverID, Date, RouteID, Distance (miles), FuelUsed (gallons), DeliveryTime (minutes). The dataset contains 10,000 records from the past year. You need to create a visualization that allows management to quickly compare the average fuel efficiency (miles per gallon) of drivers and also see how consistent each driver's efficiency is. Which of the following approaches is the best course of action?

Accepted Answer

Create a box plot grouped by DriverID showing the distribution of MPG for each driver.. A box plot grouped by DriverID is the best choice because it simultaneously shows the central tendency (median MPG) and the spread (interquartile range and outliers) of each driver's fuel efficiency. This allows management to quickly compare average efficiency across drivers while also assessing consistency—drivers with narrow boxes are more consistent, while those with wide boxes or many outliers are erratic. The other options either fail to show distribution (bar chart, line chart) or require manual interpretation of consistency (scatter plot).

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Create a line chart with Date on the x-axis and MPG on the y-axis, with separate lines for each driver.

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Create a scatter plot with Distance on the x-axis and FuelUsed on the y-axis, color-coded by DriverID.

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Create a bar chart showing the average MPG for each driver.

Question 3

Drag and drop the steps to clean a dataset with missing values in the correct order.

Question 4

Drag and drop the steps to resolve data integration conflicts in the correct order.

Question 5

Match each data type to its example.

Question 6

Match each data analysis tool to its primary function.

Question 7

A company needs to visualize the trend of monthly sales revenue over the past two years. Which chart type is most appropriate?

Accepted Answer

Line chart. Option B is correct because line charts are best for showing trends over time. Option A (pie) is for parts of a whole; Option C (scatter) is for relationships between variables; Option D (bar) compares categories but not trends as clearly.

Answer

Bar chart

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Scatter plot

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Pie chart

Question 8

A data analyst creates a dashboard showing average order value by region. The chart indicates that one region has an unusually high average. Investigation reveals that the region has very few orders, but one large purchase inflates the average. Which data transformation should the analyst apply to improve the visualization?

Accepted Answer

Use median instead of mean for aggregation. Option A is correct because using an appropriate aggregation like median or grouping with sufficient data can mitigate the impact of outliers. Other options do not address the root cause.

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Apply logarithmic scaling to the y-axis

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Change the chart type to a pie chart

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Remove all outliers from the dataset

Question 9

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. Option D is correct because a choropleth map adjusted for per-capita values properly normalizes by population. Other options either do not normalize or distort the data.

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 10

A marketing team wants to compare the growth rates of four product categories over the last quarter. Which chart type would best display this?

Accepted Answer

Bar chart. Option C is correct because a bar chart comparing growth percentages across categories is clear and straightforward. Other options are less effective for comparing discrete metrics.

Answer

Pie chart

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Stacked bar chart

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Line chart

Question 11

A scatter plot of advertising spend vs. revenue shows no clear correlation, but the analyst suspects a relationship exists. Which addition to the plot could help reveal a hidden trend?

Accepted Answer

Add a trendline. Option A is correct because adding a trendline (e.g., linear regression) can reveal patterns in noisy data. Other options may obscure or not address the issue.

Answer

Change to a bar chart

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Increase the marker size

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Remove data points with low spend

Question 12

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. Option C is correct because PCA (or t-SNE) is designed for dimensionality reduction to visualize clusters. Other options are less effective for high-dimensional data.

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Heatmap of correlations

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Scatter matrix (pairplot)

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Parallel coordinates plot

Question 13

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. Option B is correct because multiple line chart lines allow comparison of trends across regions. A stacked bar would show composition, not trends.

Answer

Pie chart

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Stacked bar chart

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Area chart

Question 14

An executive dashboard must display high-level KPIs such as current revenue, profit margin, and customer count. Which visualization type is most appropriate for each KPI?

Accepted Answer

KPI card showing value and variance. Option D is correct because KPI cards (or tiles) display a single metric clearly and concisely. Other options are less effective for immediate understanding.

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Pie chart

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Sparkline for each KPI

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Gauge chart

Question 15

A dataset contains salaries ranging from $25,000 to $2,500,000, with most salaries under $100,000. Which chart type best shows the distribution without distortion from extreme values?

Accepted Answer

Box plot. Option B is correct because box plots display distribution with outliers clearly separated, unaffected by extreme values in terms of scale. Histograms may compress the bulk of data.

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Scatter plot

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Histogram with equal bin widths

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Line chart