CompTIA Data+ (DA0-002)VisualizationMedium
A data analyst is tasked with creating a report that compares the market share of five major competitors in the smartphone industry over the past decade. The report needs to clearly show how each competitor's share has changed relative to the total market and to each other. Which chart type would be MOST suitable for this analysis?
- ALine chart with multiple lines
- BBar chart
- CScatter plot
- DStacked area chart
Show answer & explanationAnswer & explanation
Correct answer: D. Stacked area chart
A stacked area chart is ideal for showing how the composition of a whole changes over time. In this scenario, it would effectively visualize how each competitor's market share (a part of the whole market) has evolved over the decade, while also showing the total market size and the relative proportions of each competitor.
Why the other options are wrong
- A. While a line chart can show individual market share trends, it doesn't clearly illustrate the 'part-to-whole' aspect or total market composition as effectively as a stacked area chart.
- B. Bar charts are generally used for comparing discrete categories or showing change over time for individual categories, but not as effective for showing composition of a whole that changes over time.
- C. Scatter plots are used for showing relationships between two numerical variables, not for market share composition over time.
Stacked Area Chart
A chart that displays the contribution of different categories to a total over time, where each series is stacked on top of the previous one.
- Shows part-to-whole relationships over time.
- Illustrates changes in composition.
- Total area represents the sum of all categories.
Memory trick: Market's layers, changing bright, stacked areas show the competitive fight.