Name:__________________________________ Class:___________ Date:___________
Statistics
Interquartile Range (IQR) Class Work
For Exercises 1-2, identify the range, median, Q1, Q3, and interquartile range
(IQR).
1. Weights of pumpkins (in lbs)
5
16
23
20
15
7
8
11
12
24
16
73
68
91
2. Panthers’ points during the basketball season
82
95
85
80
78
80
90
86
72
87
82
86
96
3. The data below represents a class’s grades on a science exam. Find the measure of
variation by calculating the interquartile range.
97
84
93
76
70
85
83
99
100
96
76
74
4. Ms. Wheeler asked each student in her class to write their age in months on a sticky
note. The 27 students in the class brought their sticky note to the front of the room and
posted them in order on the white board. The data set is listed below in order from least
to greatest. What are some observations that can be made from the data display?
1
(Hint: What statements could you make about the data using 25%? ? 75%? Etc.)
2
130
137
143
130
137
143
131
138
144
131
139
145
132
139
147
132
140
149
132
141
150
133
142
134
142
136
142
5. Write a data set of any 7 numbers that has all of the characteristics given below.
•
•
•
range equal to 18
interquartile range equal to 8
median equal to 7
Challenge:
Write a data set of any 8 numbers that has all of the characteristics given below.
•
•
•
•
range equal to 22
interquartile range equal to 7
median equal to 11
mean equal to 15.75
Name:__________________________________ Class:___________ Date:___________
Statistics
Interquartile Range (IQR) Class Work
For Exercises 1-2, identify the range, median, Q1, Q3, and interquartile range
(IQR).
1. Weights of pumpkins (in lbs)
5
16
23
20
15
7
8
11
12
24
16
Range = 19 pounds
Q3 = 20 pounds
Median = 15 pounds
IQR = 12 pounds
Q1 = 8 pounds
2. Panthers’ points during the basketball season
83
95
85
80
78
80
89
86
72
87
82
86
96
73
68
91
Range = 28 points
Q3 = 88 points
Median = 84 points
IQR = 9 points
Q1 = 79 points
3. The data below represents a class’s grades on a science exam. Find the measure of
variation by calculating the interquartile range.
97
84
93
76
70
Range = 30 points
85
83
99
100
95
Q3 = 96 points
Median = 84.5 points
Q1 = 76 points
IQR = 20 points 76
74
4. Ms. Wheeler asked each student in her class to write their age in months on a sticky
note. The 27 students in the class brought their sticky note to the front of the room and
posted them in order on the white board. The data set is listed below in order from least
to greatest. What are some observations that can be made from the data display?
1
(Hint: What statements could you make about the data using 25%? ? 75%? Etc.)
2
130
137
143
130
137
143
131
138
144
131
139
145
132
139
147
132
140
149
132
141
150
133
142
134
142
Range = 20 months
Q3 =143 months
Median = 139 months
IQR = 11 months
136
142
Q1 = 132 months
Statements could include:
•¼ of the students in the class are between 130 and 132 months old.
•25% of the students in the class are 143 months old or older.
•½ of the class is between 132 and 143 months old.
5. Write a data set of any 7 numbers that has all of the characteristics given below.
•
•
•
range equal to 18
interquartile range equal to 8
median equal to 7
There are many possible solutions. Three possibilities include:
1)
2
6
6
7
10
14
20
2)
7
7
7
7
15
15
25
3)
1
2
6
7
9
10
19
Challenge:
Write a data set of any 8 numbers that has all of the characteristics given below.
•
•
•
•
range equal to 32
interquartile range equal to 7
median equal to 11
mean equal to 15.75 (Data points must sum to 126)
10
10
10
10
12
17
17
40