Name: _______________________
Statistics – Comparing Populations
1
Mr. Cellan surveyed the students in his first period gym
class to find out how many times they exercised this
month. The box plot shows the results.
Date: _______
Class: Pre-Algebra
3
Part A Find the following values.
Sheet # 09-04
Kacey surveyed a different group of students in her
science and math classes. The double box plot shows
the results for both classes.
What conclusion can be drawn based on the data?
Minimum:
First Quartile:
A
The students in both classes posted about the same
number of blogs because their range is the same.
Maximum:
Third Quartile:
B
Overall the students in the math class posted more blogs
because the left half of the box plot is longer.
Range:
Interquartile Range:
C
Overall the students in the science class posted more
blogs because the median is higher.
D
Since both classes share the same maximum, they
generally posted the same amount of blogs.
Part B What is the median? What does the median
represent?
4
Which of the following is not true about the double box
plot?
Part C Make a conclusion about the different lengths of the
sections.
2
Dominic asked a random sample of students in North
Middle School and South Middle School how far they
travel to school. His results are shown in the box plots
below.
A
The data for the steel coaster is symmetric.
B
The data for the steel coaster is not symmetric.
C
The fastest steel coaster travels 135 miles per hour.
D
The slowest wooden coaster ravels 60 miles per hour.
5
The double dot plot below shows the daily low
temperatures of two cities in January.
Part A: Which school’s students have the greater variability in
distance they travel to school? Explain how you know.
Which of the following statements about the two
populations is true?
Part B: Which school’s students typically have the greater
distance to travel to school? Relate your reasoning to measures of
center or measures of variability.
A
The medians are the same.
B
The interquartile ranges are the same.
C
The temperatures for City A are typically higher.
D
The temperatures for City B are more consistent.
6
A random sample of the numbers of miles that two
people drove each day last month is shown below.
9
Martina: 32, 41, 36, 54, 32, 12, 24
William: 26, 24, 10, 18, 40, 21, 15
The box plot below shows the scores on last week’s
test for 10 randomly selected students from each of Mr.
Brenner’s two mathematics classes.
Which of these statements is best supported by these
data?
A William has the greater median and mean, so he
generally drove farther last month than Martina.
B
Martina has the greater median and mean, so she
generally drove farther last month than William.
C William has the greater median and Martina has the
greater mean, so William generally drove farther last
month than Martina.
D Martina has the greater median and William has the
greater mean, so Martina generally drove farther last
month than William.
7
The number of calories in the five top-selling
sandwiches at two sandwich shops are shown below.
Which statement about the performance of the students in
the two classes is best supported by the data from these
samples?
A The two classes performed equally well because the
range of each class is the same.
B
The two classes performed equally well because the
greatest score in each class is the same.
C The students in Class Y generally performed better than
the students in Class X because most students in Class Y
had a score greater than 70.
D The students in Class Y generally performed better than
the students in Class X because the median of Class Y is
greater than that of Class X.
10
Two schools used can recycling as a school
project last year. They both recorded the number
of cans recycled per week for 20 weeks. The data
is displayed in the box-and-whisker plots below.
Which statement about the sandwich calories at each
sandwich shop is true?
A The mean for Sal’s Subs is less than the mean for Bert’s
Bites.
B
The mean for Sal’s Subs is greater than the mean for
Bert’s Bites.
C The mean absolute deviation for Sal’s Subs is less than
Which conclusion is best supported by the data?
A The range of the Lincoln School data was 40 greater
than the range of the Adams School data.
the mean absolute deviation for Bert’s Bites.
D The mean absolute deviation for Sal’s Subs is greater
than the mean absolute deviation for Bert’s Bites.
B
The median numbers of cans collected at both schools
was approximately the same.
C Adams School had the least and the greatest number of
8
A scientist measured the lengths of 12 scrub jays and
12 blue jays. She made these box-and-whisker plots of
the two sets of data.
What conclusion can the scientist draw from the data?
A
The median length for both types of jays is 30 cm.
B
The ranges of the lengths of the blue jays and of the
scrub jays are the same.
C
One-half of both groups of jays are more than 30.5 cm
long.
D
One-half of the blue jays and three-fourths of the scrub
cans recycled per week.
D Lincoln School recycled more cans per week than
Adams School for more than half of the weeks in the 20week period.
11
Amy made these box-and-whisker plots showing the
heights of her sunflowers in 2005 and 2006. Use the
plots to answer parts A & B.
12
Examine these two dot plots:
PLOT A
Part A: Which statement is true about the range of the heights for
the two years?
A
They are the same.
B
The range is greater in 2005.
C
The range is greater in 2006.
D
It is impossible to compare ranges.
Part B: Based on the data, which conclusion is NOT true?
A
Both years one-fourth of the plants were less than 6 feet
tall.
B
Both years half of the plants were at least 7 feet tall.
C
Both years the median height of the plants was 7 feet.
D
Both years one-fourth of the plants were more than 8
feet tall.
PLOT B
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10
Without calculating, tell which dot plot will have the greatest
mean absolute deviation. Explain your reasoning.