DSE Exploratory Data Analysis Techniques 5

Question 1

Which plot is most suitable for visualizing changes in a continuous variable over time?

Accepted Answer

Line chart

Answer

A line chart connects sequential data points in chronological order, making trends, cycles, and anomalies in time-series data easy to see.

Question 2

What is the purpose of a pivot table in EDA?

Accepted Answer

To summarize data by aggregating values across two or more categorical dimensions

Answer

A pivot table reorganizes data into a matrix where rows and columns represent categorical variables and cells contain aggregated statistics like counts or means.

Question 3

A dataset has a bimodal distribution. What does this likely indicate?

Accepted Answer

The dataset may contain two distinct subpopulations or groups

Answer

Two peaks (modes) in a distribution often suggest the presence of two distinct subgroups with different characteristic values mixed into a single dataset.

Question 4

Which of the following is a key step in univariate EDA for a continuous variable?

Accepted Answer

Examining the distribution shape, central tendency, spread, and outliers

Answer

Univariate EDA for a continuous variable involves summarizing and visualizing its distribution shape, mean/median, standard deviation, and extreme values.

Question 5

What does Spearman's rank correlation measure that Pearson's correlation does not?

Accepted Answer

Monotonic relationships, including nonlinear ones, between two variables

Answer

Spearman's correlation computes Pearson's r on the ranks of the data, capturing any monotonic relationship (not just linear) and being robust to outliers.

DSE - Data Science Practice Test

DSE - Data Science Practice Test

DSE Exploratory Data Analysis Techniques 5