DA0-002 Data Analysis Practice Question
Which TWO of the following are components of time series data?
⚠ Common exam trap
DA0-002 often tests whether candidates confuse statistical summary measures (mean, median, variance) with the structural components of time series (trend, seasonality, cyclicality, irregular), so candidates must recognize that the question asks for components, not statistics.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Trend
Trend (C) is a core component of time series data because it represents the long-term, systematic increase or decrease in the series level over time, which is exactly what decomposition methods (e.g., additive or multiplicative decomposition) isolate. Seasonality (D) is also a core component because it captures regular, calendar-linked repeating patterns (e.g., daily, weekly, monthly, or quarterly cycles) that recur with a fixed period. By contrast, Mean (A), Variance (B), and Median (E) are descriptive statistics or summary measures of a distribution, not structural components of a time series; they describe the data's central tendency or spread rather than the temporal dynamics that decomposition separates.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Mean
Why it's wrong here
Mean is an aggregate statistic, not a component of time series data. It is tempting because averages are commonly calculated across a series for reporting, yet the actual components are trend, seasonality, cyclicity and irregular (random) variation.
- ✗
Variance
Why it's wrong here
Variance measures dispersion around a mean, not a structural component of time series data, which comprises trend, seasonality, cyclicity and irregularity. It is tempting because variance appears in forecasting diagnostics and stationarity testing, and would be the right focus when assessing volatility or spread within a dataset rather than identifying its temporal components.
- ✓
Trend
Why this is correct
Trend is the long-term directional movement of a series over time, rising, falling or flat, ignoring short-term fluctuations. It is a core time series component alongside seasonality, cyclical variation and irregular residuals, so it satisfies the question's requirement.
- ✓
Seasonality
Why this is correct
Seasonality is a repeating, calendar-linked pattern within a fixed period, such as higher traffic each weekday. It is one of the four standard time series components, alongside trend, cyclical variation and irregular noise, so it qualifies as a component of time series data.
- ✗
Median
Why it's wrong here
Median is a descriptive statistic summarising a distribution, not a structural component of time series data. It is tempting because analysts routinely compute medians when smoothing or comparing series, but the components are trend, seasonality, cyclicity and irregular variation.
Go deeper
Related to this question
About these practice questions
This DA0-002 question is part of Courseiva's 1,004-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official CompTIA exam blueprint
This DA0-002 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DA0-002 exam.