NAME ____________________________________________ DATE _____________________________ PERIOD _____________
Practice 7.12(C)
SCORE __________
Compare two populations based on data in random samples from these populations, including informal comparative
inferences about differences between the two populations.
Multi-Step Example
Each month Liberty School publishes a magazine. As part of a market research project, Ted surveys
24 people, asking them the number of magazines they have purchased in the past year. The results
of the survey are shown in the double box plot. What is the median and interquartile range of each
set of data? What inference can be made about the number of magazines purchased?
Median
IQR
Liberty Students
Non-Students
5.5
1.5
8 - 2.5 = 5.5
3.5 - 0 = 3.5
The Liberty students data centers around 5.5 magazines with an interquartile range of 5.5.
The non-students data centers around 1.5 magazines with an interquartile range of 3.5.
So, the Liberty students generally purchase more magazines than non-students.
1 The dot plot shows the number of hours students spent
last week on social networking sites. Which is NOT an
inference that can be made about the two populations?
2 The results of a survey that asked 50 seventh graders
how many hours they play video games are shown in
the double box plot. Which statement is true?
F There is no difference in the maximum values.
A Females typically spend more time than males on the
sites.
G The difference in the maximum values is 1.5 hours.
H The median for the girls is 0.5 hour.
B Females typically spend less time than males on the
sites.
J The third quartile for the boys is 2.5 hours.
C The range for males is greater than the range for
females.
D The interquartile range for the males is 4 hours.
Course 2 • Measurement and Data TX145 NAME ____________________________________________ DATE _____________________________ PERIOD _____________
Practice 7.12(C) (continued)
3 A study of ornamental grasses was conducted at two
local plant retailers. The heights of 20 plants are
shown in the table. How much greater is the mean
height at Al’s Garden Center than the mean height at
Bernard’s
Nursery?
Ornamental Grass Height (in.)
Bernard’s Nursery Al’s Garden Center
11
12
12
14
11
16
10
18
14
10
16
12
10
14
12
20
13
21
9
18
A 1.5 in.
SCORE __________
5 The state highway patrol inspected vehicles on two
highways. The double dot plot shows the numbers of
vehicle violations that they found. Which inference
can be made about the two populations?
A The shapes of both plots are symmetrical.
B The data spreads of both populations are the same.
C The interquartile range for Route 9 is 0.5 and the
interquartile range for Interstate 45 is 2
.
D The median for Route 9 is 1 and the median for
interstate 45 is 2.
B 3.7 in.
C 4.0 in.
D 5.5 in.
4 Bertha randomly surveyed students in two classes
about the number of hours they read per week. Which
inference can be made?
6 Camille surveyed students on the volleyball and karate
teams about the number of times they ate out last
week. What is the difference in the interquartile
ranges?
F Both box plots are symmetrical.
G The difference in the medians is 2.
H The interquartile range for history class is 2 and the
interquartile range for language class is 4.
Record your answer and fill in the bubbles on your
answer document. Be sure to use the correct place
value.
J Seventy-five percent of the language class plays video
games for 3 or more hours.
TX146 Course 2 • Measurement and Data NAME ____________________________________________ DATE _____________________________ PERIOD _____________
Practice 7.12(C)
SCORE __________
Student Recording Sheet
Fill in the correct answer. For gridded-response questions, write your answers in the boxes on the answer grid and
fill in the bubbles to match your answers.
1
2
3
4
5
6
Course 2 • Measurement and Data
TX147