Understanding Q1, Q3, and IQR

The video from MooMooMath explains how to find the first quartile (Q1), third quartile (Q3), and the interquartile range (IQR) of a data set. It provides a step-by-step guide to ordering numbers, identifying extremes, and calculating medians to determine Q1 and Q3. The video includes two example data sets to illustrate the process, showing how to calculate the IQR by subtracting Q1 from Q3. The tutorial is designed to help viewers understand these concepts, especially when setting up box plots or box-and-whisker plots.

What is the primary purpose of understanding Q1, Q3, and IQR?

• To solve algebraic equations

• To set up box plots

• To create pie charts

• To calculate averages

What is the first step in calculating Q1, Q3, and IQR?

• Calculate the range

• Find the median

• Order numbers from least to greatest

• Identify the extremes

Which of the following is used to find Q3?

• Median of the entire data set

• Median of the lower half of the data

• Median of the upper half of the data

• Average of the extremes

In the first example, what is the median of the entire data set?

• 20

• 16

• 29

• 34

What is the IQR in the first example?

• 20

• 13

• 27

• 7

In the second example, what is the median of the data set?

• 81.5

• 82

• 90

• 80

What is the Q1 value in the second example?

• 90

• 80

• 70

• 65

How is the IQR calculated?

• By multiplying Q1 and Q3

• By subtracting Q1 from Q3

• By adding Q1 and Q3

• By dividing Q3 by Q1

What is the IQR in the second example?

• 10

• 25

• 15

• 20

What is the final step in calculating the IQR?

• Ordering the numbers

• Identifying the extremes

• Subtracting the lower quartile from the upper quartile

• Finding the median of the entire data set