Boxplots and Outliers

Front

What is a boxplot?

Back

A boxplot, or box-and-whisker plot, is a graphical representation of a dataset that displays its minimum, first quartile (Q1), median, third quartile (Q3), and maximum values.

Front

What does IQR stand for?

Back

IQR stands for Interquartile Range, which is the difference between the first quartile (Q1) and the third quartile (Q3) in a dataset.

Front

How do you calculate the IQR?

Back

IQR = Q3 - Q1.

Front

What is the purpose of a boxplot?

Back

A boxplot is used to visually summarize the distribution of a dataset, identify outliers, and compare different datasets.

Front

What is an outlier in a dataset?

Back

An outlier is a data point that is significantly different from the other observations in a dataset, often identified as being more than 1.5 times the IQR above Q3 or below Q1.

Front

What does the median represent in a boxplot?

Back

The median represents the middle value of a dataset when it is ordered from least to greatest, dividing the dataset into two equal halves.

Front

What are quartiles?

Back

Quartiles are values that divide a dataset into four equal parts, with Q1 being the first quartile (25th percentile), Q2 being the median (50th percentile), and Q3 being the third quartile (75th percentile).

Front

How can you identify the lower quartile (Q1) from a boxplot?

Back

The lower quartile (Q1) is represented by the left edge of the box in a boxplot.

Front

What does the whisker in a boxplot represent?

Back

The whiskers in a boxplot extend from the quartiles to the minimum and maximum values of the dataset, excluding outliers.

Front

What is the significance of the interquartile range (IQR)?

Back

The IQR is significant because it measures the spread of the middle 50% of the data, providing a robust measure of variability that is less affected by outliers.