Introdução a estatistica

9 30 36 210 258 149 134
10 59 58 168 156 131 90
11 55 58 223 211 130 124
12 21 46 248 163 106 108
13 52 26 151 99 108 110
14 61 28 220 162 143 144
15 56 53 211 253 76 81
2.2 Organizing and Graphing Quantitative Data 59
16 55 33 104 119 124 109
17 52 62 262 231 89 81
18 33 35 122 258 107 85
19 34 31 136 138 103 135
20 33 29 156 139 100 105
21 31 20 222 232 98 97
22 27 34 174 140 112 132
23 34 50 230 236 121 113
24 48 47 167 234 105 149
25 25 44 262 149 81 99
26 47 21 234 196 134 149
27 49 55 146 202 113 75
28 22 43 214 229 93 85
29 35 53 130 220 124 126
30 29 31 232 190 76 148
2.14 a. Construct a frequency distribution table for ages of male 
participants using the classes 20–29, 30–39, 40–49, 50–59, 
and 60–69.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the frequency distribution of part a.
d. What percentage of the male participants are younger 
than 40?
2.15 a. Construct a frequency distribution table for ages of female 
participants using the classes 20–29, 30–39, 40–49, 50–59, 
and 60–69.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the frequency distribution of part a.
d. What percentage of the female participants are younger than 40?
e. Compare the histograms for Exercises 2.14 and 2.15 and 
mention the similarities and differences.
2.16 a. Construct a frequency distribution table for weights of male 
participants using the classes 91–125, 126–160, 161–195, 
196–230, and 231–265.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the relative frequency distribution 
of part b.
d. What percentage of the male participants have weights less 
than 161 lbs?
2.17 a. Construct a frequency distribution table for weights of female 
participants using the classes 91–125, 126–160, 161–195, 
196–230, and 231–265.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the relative frequency distribution 
of part a.
d. What percentage of the female participants have weights less 
than 161 lbs?
e. Compare the histograms for Exercises 2.16 and 2.17 and 
mention the similarities and differences.
2.18 a. Construct a frequency distribution table for blood glucose 
levels of male participants using the classes 75–89, 90–104, 
105–119, 120–134, and 135–149.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the percentage distribution of 
part b.
d. What percentage of the male participants have blood glucose 
levels more than 119?
e. Prepare the cumulative frequency, cumulative relative fre-
quency, and cumulative percentage distributions using the 
table of part a.
2.19 a. Construct a frequency distribution table for blood glucose 
levels of female participants using the classes 75–89, 90–104, 
105–119, 120–134, and 135–149.
b. Calculate the relative frequency and percentage for each 
class.
c. Construct a histogram for the percentage distribution of 
part b.
d. What percentage of the female participants have blood 
glucose levels more than 119?
e. Compare the histograms for Exercises 2.18 and 2.19 and 
mention the similarities and differences.
f. Prepare the cumulative frequency, cumulative relative fre-
quency, and cumulative percentage distributions using the 
table of part a.
2.20 The following table lists the number of strikeouts per game 
(K/game) for each of the 30 Major League baseball teams during the 
2014 regular season.
Participant
Age 
(Males)
Age 
(Females)
Weight 
(Males)
Weight 
(Females)
Blood 
Glucose 
(Males)
Blood 
Glucose 
(Females)
60 Chapter 2 Organizing and Graphing Data
Team K/game Team K/game Team K/game
Arizona Diamondbacks 7.89 Houston Astros 7.02 Philadelphia Phillies 7.75
Atlanta Braves 8.03 Kansas City Royals 7.21 Pittsburgh Pirates 7.58
Baltimore Orioles 7.25 Los Angeles Angels 8.28 San Diego Padres 7.93
Boston Red Sox 7.49 Los Angeles Dodgers 8.48 San Francisco Giants 7.48
Chicago Cubs 8.09 Miami Marlins 7.35 Seattle Mariners 8.13
Chicago White Sox 7.11 Milwaukee Brewers 7.69 St. Louis Cardinals 7.54
Cincinnati Reds 7.96 Minnesota Twins 6.36 Tampa Bay Rays 8.87
Cleveland Indians 8.95 New York Mets 8.04 Texas Rangers 6.85
Colorado Rockies 6.63 New York Yankees 8.46 Toronto Blue Jays 7.40
Detroit Tigers 7.68 Oakland Athletics 6.68 Washington Nationals 7.95
Data source: MLB.com.
a. Construct a frequency distribution table. Take 6.30 as the lower 
boundary of the first class and .55 as the width of each class.
b. Prepare the relative frequency and percentage distribution 
columns for the frequency distribution table of part a.
2.21 The following data give the number of turnovers (fumbles and 
interceptions) made by both teams in each of the football games 
played by a university during the 2014 and 2015 seasons.
2 3 1 1 6 5 3 5 5 1 5 2 1
5 3 4 4 5 8 4 5 2 2 2 6
a. Construct a frequency distribution table for these data using 
single-valued classes.
b. Calculate the relative frequency and percentage for each class.
c. What is the relative frequency of games in which there were 
4 or 5 turnovers?
d. Draw a bar graph for the frequency distribution of part a.
2.22 The following table gives the frequency distribution for the 
numbers of parking tickets received on the campus of a university 
during the past week by 200 students.
 Number of Tickets Number of Students
 0 59
 1 44
 2 37
 3 32
 4 28
Draw two bar graphs for these data, the first without truncating the 
frequency axis and the second by truncating the frequency axis. In the 
second case, mark the frequencies on the vertical axis starting with 
25. Briefly comment on the two bar graphs.
Another technique that is used to present quantitative data in condensed form is the stem-and-
leaf display. An advantage of a stem-and-leaf display over a frequency distribution is that by 
preparing a stem-and-leaf display we do not lose information on individual observations. A stem-
and-leaf display is constructed only for quantitative data.
2.3 Stem-and-Leaf Displays
Stem-and-Leaf Display In a stem-and-leaf display of quantitative data, each value is divided 
into two portions—a stem and a leaf. The leaves for each stem are shown separately in a display.
 Example 2–8 describes the procedure for constructing a stem-and-leaf display.
EXAMPLE 2–8 Scores of Students on a Statistics Test
The following are the scores of 30 college students on a statistics test.
75 52 80 96 65 79 71 87 93 95
69 72 81 61 76 86 79 68 50 92
83 84 77 64 71 87 72 92 57 98
Construct a stem-and-leaf display.
Constructing a stem-and-leaf 
display for two-digit numbers.
2.3 Stem-and-Leaf Displays 61
Solution To construct a stem-and-leaf display for these scores, we split each score into two 
parts. The first part contains the first digit of a score, which is called the stem. The second part 
contains the second digit of a score, which is called the leaf. Thus, for the score of the first stu-
dent, which is 75, 7 is the stem and 5 is the leaf. For the score of the second student, which is 52, 
the stem is 5 and the leaf is 2. We observe from the data that the stems for all scores are 5, 6, 7, 
8, and 9 because all these scores lie in the range 50 to 98. To create a stem-and-leaf display, we 
draw a vertical line and write the stems on the left side of it, arranged in increasing order, as 
shown in Figure 2.15.
Figure 2.15 Stem-and-leaf display.Stems
5 2 Leaf for 52
6
7 5 Leaf for 75
8
9
 After we have listed the stems, we read the leaves for all scores and record them next 
to the corresponding stems on the right