EDA Quiz May 16, 2025

What does EDA stand for?

• Exploratory Data Analysis

• Experimental Data Assessment

• External Data Application

• Efficient Data Arrangement

• None of the above

Answer explanation

EDA stands for Exploratory Data Analysis, which is a crucial step in data analysis that involves summarizing and visualizing datasets to understand their main characteristics before applying more formal statistical methods.

What is the main goal of univariate analysis?

• To compare two datasets

• To understand individual feature properties

• To analyze time series data

• To predict future trends

• To find clusters

Answer explanation

The main goal of univariate analysis is to understand individual feature properties. It focuses on analyzing one variable at a time to summarize its characteristics, rather than comparing datasets or predicting trends.

Which of the following is a graphical method for univariate analysis?

• Scatter plot

• Histogram

• Heatmap

• Pair plot

• Pie chart

Answer explanation

A histogram is a graphical method for univariate analysis, displaying the distribution of a single variable by showing the frequency of data points within specified ranges. Other options like scatter plots and pair plots involve multiple variables.

Which summary statistic tells you the "average" value in a dataset?

• Mode

• Median

• Mean

• Range

• Variance

Answer explanation

The mean is the sum of all values in a dataset divided by the number of values, representing the 'average' value. In contrast, the mode is the most frequent value, and the median is the middle value when sorted.

What does a box plot help you identify?

• Correlation between features

• Outliers and spread of data

• Time trends

• Data types

• Missing values

Answer explanation

A box plot visually summarizes data by showing its median, quartiles, and potential outliers. It effectively highlights outliers and the spread of data, making it easier to identify variations within the dataset.

What is the main purpose of bivariate analysis?

• To understand one variable

• To understand the relationship between two features

• To reduce data dimensions

• To visualize time series

• To find outliers

Answer explanation

The main purpose of bivariate analysis is to understand the relationship between two features. This analysis helps identify correlations, patterns, and interactions that may exist between the variables.

Which plot is commonly used to show the relationship between two numerical variables?

• Bar chart

• Box plot

• Scatter plot

• Pie chart

• Histogram

Answer explanation

A scatter plot is the best choice for showing the relationship between two numerical variables, as it displays data points on a Cartesian plane, allowing for easy visualization of correlations and trends.

What statistical measure tells you how two numerical variables move together?

• Skewness

• Correlation

• Mode

• Range

• Kurtosis

Answer explanation

The correct answer is Correlation, which measures how two numerical variables move together. A positive correlation indicates they move in the same direction, while a negative correlation indicates they move in opposite directions.

What is a contingency table used for?

• To summarize one variable

• To visualize time trends

• To analyze the relationship between two categorical variables

• To calculate the mean

• To find missing values

Answer explanation

A contingency table is used to analyze the relationship between two categorical variables by displaying the frequency distribution of the variables. This helps in understanding how the categories interact with each other.

Which test is often used to check the relationship between two categorical variables?

• t-test

• ANOVA

• Chi-square test

• Regression

• Pearson test

Answer explanation

The Chi-square test is specifically designed to assess the relationship between two categorical variables by comparing observed frequencies with expected frequencies, making it the correct choice for this question.