IQR And Box Plots Flashcards
(25 cards)
What is the interquartile range (IQR)?
The interquartile range (IQR) is the difference between the first quartile (Q1) and the third quartile (Q3).
True or False: The IQR measures the spread of the middle 50% of data.
True
Fill in the blank: The formula for calculating IQR is _____ = Q3 - Q1.
IQR
What does Q1 represent in a data set?
Q1 represents the first quartile, which is the median of the lower half of the data.
What does Q3 represent in a data set?
Q3 represents the third quartile, which is the median of the upper half of the data.
How is the median calculated in a data set?
The median is the middle value when the data is ordered from least to greatest.
What is a box plot?
A box plot is a graphical representation of data that shows the distribution through five summary statistics: minimum, first quartile (Q1), median, third quartile (Q3), and maximum.
True or False: A box plot can show outliers in a data set.
True
In a box plot, what do the ‘whiskers’ represent?
The ‘whiskers’ represent the range of the data, extending to the smallest and largest observations that are not outliers.
What is the purpose of using the interquartile range?
The IQR is used to measure the variability of a data set and to identify outliers.
Fill in the blank: In a box plot, the box represents the _____ between Q1 and Q3.
interquartile range
Multiple Choice: Which of the following is NOT a component of a box plot? A) Minimum B) Q1 C) Mean D) Maximum
C) Mean
What is an outlier in a data set?
An outlier is a data point that is significantly different from the other observations in the data set.
True or False: The IQR is affected by extreme values in the data.
False
What does it mean if the IQR is large?
A large IQR indicates that there is a wide spread of the middle 50% of the data.
What is the minimum value in a box plot?
The minimum value is the smallest observation in the data set that is not considered an outlier.
What is the maximum value in a box plot?
The maximum value is the largest observation in the data set that is not considered an outlier.
Fill in the blank: In a box plot, the median is represented by a _____ line within the box.
horizontal
How do you identify outliers in a box plot?
Outliers are typically identified as points that fall below Q1 - 1.5 * IQR or above Q3 + 1.5 * IQR.
Multiple Choice: What does a narrow box in a box plot indicate? A) High variability B) Low variability C) No variability D) None of the above
B) Low variability
What is the relationship between the IQR and the range?
The IQR focuses on the middle 50% of the data, while the range considers all data points.
True or False: The box plot can be used for both numerical and categorical data.
False
What is the significance of the median in a box plot?
The median divides the data into two equal halves and indicates the central tendency.
Fill in the blank: The IQR is a robust measure of spread because it is not affected by _____ values.
extreme
