Transcript PowerPoint 簡報 - St. Bonaventure College and High School

1B_Ch12(1)
1B_Ch2(2)
12.2 Collection and
Classification of Data
A Collection of Data
B Classification of Data
Index
1B_Ch2(3)
12.4 Presentation and Analysis
of Discrete Data
A Pie Charts
B Broken-line Graphs
C Stem-and-leaf Diagrams
D Scatter Diagrams
E Choosing Suitable Statistical
Graphs to Present Data
Index
12.1 Various Stages of Statistics
1B_Ch12(4)
 Example
Various Stages of Statistics
Collection
of Data
Organization
of Data
Analysis
of Data
Presentation
of Data
Index
12.1 Various Stages of Statistics
1B_Ch12(5)
Ryan wants to know what kinds of food are
the classmates’ favourites. Find the correct
order of the stages of the statistics procedures.
(a) Organize the data collected in a table.
(b) Set a questionnaire about the favorite food of classmates.
(c) Analyze the collected data and obtain the conclusion by
using the diagram.
(d) Use a suitable statistical diagram to present the data.
b
a
d
c
 Key Concept 12.1.1
Index
12.2 Collection and Classification of Data
A)
1B_Ch12(6)
Collection of Data
1. Previous Information
‧ Search for relevant information from books,
newspapers, magazines, world wide web, etc.
2. Questionnaire
‧ Set a questionnaire and distribute to each member
of the target group to obtain the relevant information.
Index
12.2 Collection and Classification of Data
1B_Ch12(7)
 Example
A)
Collection of Data
3. Observation
‧ Obtain the required information through direct
observation, measurement or counting.
4. Experiment
‧ Obtain the required information by doing real
experiments.
5. Interview
‧Through household surveys, street surveys or
telephone interviews to obtain the required data.
 Index 12.2
Index
12.2 Collection and Classification of Data
1B_Ch12(8)
Suggest a suitable way to collect each of the following sets of data:
(a) The weights of 30 students in a certain class.
(b) The amount of pocket money that my sister spends each day.
(c) The number of customers shopping in a store between
7:00 a.m. and 12:00 p.m.
(d) The number of births in Hong Kong from 2000 to 2005.
(a) Questionnaire
(b) Interview
(c) Observation
(d) Previous information
 Key Concept 12.2.1
Index
12.2 Collection and Classification of Data
B)
1B_Ch12(9)
Classification of Data
1. Discrete Data
‧ Discrete data can only take up certain values and
these values are usually obtained by counting, and
so are often positive integers.
E.g. the number of rotten apples in a box.
Note : Discrete data may NOT be numbers. Some examples are
people’s religions and favourite singers.
These data are called nominal data.
Index
12.2 Collection and Classification of Data
1B_Ch12(10)
 Example
B)
Classification of Data
2. Continuous Data
‧ Continuous data can take up any value within a
reasonable interval and these values are usually
obtained from measurements.
E.g. the weights of the apples in a box.
 Index 12.2
Index
12.2 Collection and Classification of Data
1B_Ch12(11)
The sports shoes sold in the department stores
1
can have sizes of 5, 5 , 6, … only, so the
2
sizes of the sports shoes are discrete data.
However, the time (measured in hours)
spent on watching TV per day can be any
value between 0 and 24, e.g. 2, 3.4, 4.15,
etc. Hence the time spent on watching TV
is a kind of continuous data.
Index
12.2 Collection and Classification of Data
1B_Ch12(12)
Determine whether each of the following sets of data is discrete or
continuous.
(a) The number of blue ball pens in a bag.
Discrete data
(b) The time that a group of students spent
on their individual presentation.
Continuous data
(c) The weights of 20 children at the age
between 6 and 10.
Continuous data
(d) The number of people who go to Central
by ferry at a particular time of day.
Discrete data
 Key Concept 12.2.2
Index
12.3 Organization of Discrete Data
1B_Ch12(13)
Organization of Discrete Data
1. We can use a frequency distribution table to organize
the data that has been collected.
2. The number of tallies recorded for each value is called
the frequency of that value.
Index
12.3 Organization of Discrete Data
1B_Ch12(14)
 Example
Organization of Discrete Data
‧
For example, the frequency distribution table below
shows the ages of 40 students in Form 1A:
Age
Tally
Number of
students
11
//
2
12
//// //// ////
15
13
//// //// //// //
17
14
//// /
6
Index
12.3 Organization of Discrete Data
1B_Ch12(15)
From the data about the favourite extra-curricula activities of 40
Form 1 students given on the left below, we can organize them
into a frequency distribution table on the right.
Index
12.3 Organization of Discrete Data
1B_Ch12(16)
Given below are the numbers of mistakes made by
40 students of Form 1A in an English dictation.
4
5
11
7
8
13
0
6
17
9
7
3
7
10
22
0
5
18
11
10
8
9
6
3
0
14
7
8
5
20
2
6
7
16
8
6
10
1
3
apple
1
The teacher arranges the number of mistakes 0 – 3 into
the first group, 4 – 7 into the second group, 8 – 11 into
the third group, 12 – 15 into the fourth group, 16 – 19
into the fifth group and 20 – 23 into the sixth group.
Now try to organize the given data into a frequency
distribution table.
Index
12.3 Organization of Discrete Data
1B_Ch12(17)
 Back to Question
According to the above data and the teacher’s arrangement, the
following frequency distribution table can be obtained.
Number of
mistakes
Tally
Number of
students
0–3
//// ////
9
4–7
//// //// ///
13
8 – 11
//// //// /
11
12 – 15
//
2
16 – 19
///
3
20 – 23
//
2
Fulfill Exercise Objective
 Key Concept 12.3.1
 Organize the given data into a frequency distribution table.
Index
12.4 Presentation and Analysis of Discrete Data
A)
1B_Ch12(18)
Pie Charts
1. Understanding Pie Charts
i. A pie chart is appropriate to present the various
statistical items as percentages of the whole.
E.g.
Favourite ball games played
by F.1 students in a school
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(19)
 Example
A)
Pie Charts
1. Understanding Pie Chart
ii. Each item can be indicated as a percentage of the
whole set of data or as the angle of the sector.
E.g.
Monthly expenditure
of a family
Monthly expenditure
of a family
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(20)
 Example
A)
Pie Charts
2. Drawing a Pie Chart
i.
Express each item as a percentage of the whole,
then calculate the angle of each sector.
ii. Construct a circle of suitable radius, and draw the
various sectors according to the angles obtained in
(i).
iii. Label clearly the item represented by each sector
and the corresponding percentage (or angle of the
sector).
iv. Give a title to the pie chart.
 Index 12.4
Index
12.4 Presentation and Analysis of Discrete Data
The pie chart shows the favourite singers of
1B_Ch12(21)
Favourite singers of
120 teenagers
120 teenagers.
(a) Find the value of x.
(b) What percentage of the teenagers are the
fans of Nick?
 Soln
(a) x° + 90° + 225° = 360°
∴
x = 360 – 90 – 225
= 45
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(22)
 Back to Question
(b) The percentage of the teenagers who are
Favourite singers of
120 teenagers
the fans of Nick
225
=
100%
360
= 62.6%
 Key Concept 12.4.1
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(23)
In a survey, 400 F.1–F.3 students were asked what kind
of music they like most.The results are shown in the
following pie chart.
Favourite kinds of music of 400
F.1–F.3 students
Index
12.4 Presentation and Analysis of Discrete Data
(a) Find the value of x in the pie chart.
1B_Ch12(24)
 Soln
(b) Find the number of students who love folk music.  Soln
(c) Among those students who love folk music, 56
are F.1 students and 49 are F.2 students.
i. Calculate the number of F.3 students who
love folk music.
 Soln
ii. Draw a pie chart to show, in percentages, the
distribution of students who love folk music
in each form.
 Soln
Index
12.4 Presentation and Analysis of Discrete Data
 Back to Question
1B_Ch12(25)
 Back to Graph
(a) 40 + 35 + 5 + x = 100
∴
x = 100 – 40 – 35 – 5
= 20
(b) Number of students who love folk music
= 400 × 35%
= 140
(c) i. Number of F.3 students who love
folk music
= 140 – 56 – 49
= 35
Index
12.4 Presentation and Analysis of Discrete Data
 Back to Question
1B_Ch12(26)
 Back to Graph
(c) ii. We first construct the following table:
Total:
140
100%
360o
Index
12.4 Presentation and Analysis of Discrete Data
 Back to Question
(c) ii.
1B_Ch12(27)
 Back to Graph
The required pie chart:
The distribution of students who love
folk music in each form
Fulfill Exercise Objective
 Miscellaneous problems.
 Key Concept 12.4.2
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(28)
 Example
B)
Broken-line Graphs
1. Understanding Broken-line Graphs
i. A broken-line graph is used to show the change
in the data over a period of time and their overall
tendency.
E.g.
Annual profits of a company
Year
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(29)
 Example
B)
Broken-line Graphs
2. Drawing a Broken-line Graph
i. List on the horizontal axis, the time of happenings
of the statistical item in order of magnitude.
ii. List the frequencies of the item on the vertical axis.
iii. All necessary scales, items, values and units
should be shown clearly on the two axes.
iv. Use ‘‧’ or ‘x’ to indicate points that represent the
frequency of the corresponding statistical item.
v. Join adjacent points by line segments.
vi. Give a title to the broken-line graph.
 Index 12.4
Index
12.4 Presentation and Analysis of Discrete Data
The broken-line graph shows
the number of visitors to the
park in a particular day.
Number of Visitors to the Park in a
Particular Day
160
140
Number of Visitors
(a) Which period of time did
the number of visitors
increase the most? What
was the increase in
visitors?
1B_Ch12(30)
120
100
80
60
40
20
0
12:00
14:00
16:00
18:00
20:00
22:00
Time of Day
(b) Find the difference in the number of visitors
between 14:00 and 18:00 in that particular day.
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(31)
Number of Visitors to the Park in a
Particular Day
 Back to Question
160
Number of Visitors
140
120
100
80
60
40
20
0
12:00
14:00
16:00
18:00
20:00
22:00
Time of Day
(a) From 12:00 to 14:00. The increase in visitors was 70.
(b) The difference in the number of visitors between 14:00 and
18:00 in that particular day
= 120 – 80
 Key Concept 12.4.3
= 40
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(32)
The given bar chart shows
the monthly rainfall of a
certain city last year. Paul
l i v e s i n t h a t c i t y. T h e
windows in his home leaked
badly in the four most heavy
rainfall months last year. He
intends to fix the leakage
before those four rainy
months come again this year.
Monthly rainfall (mm)
Monthly rainfall of a certain city last year
Month
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(33)
(a) With reference to last year’s data shown above, before
which month should Paul fix the windows?
(b) Draw a broken-line graph to present the
monthly rainfall of that city in last year.
 Soln
(a) The four most heavy rainfall months last year
were April, May, June and July.
∴ Paul should fix the windows before April.
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(34)
 Back to Question
(b) The broken-line graph showing the monthly rainfall
of that city last year is as follows:
Monthly rainfall of a certain city last year
Fulfill Exercise Objective
Monthly rainfall (mm)
 Miscellaneous
problems.
 Key Concept 12.4.4
Month
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(35)
 Example
C)
Stem-and-leaf Diagrams
1. Understanding Stem-and-leaf Diagrams
i. A stem-and-leaf diagram is used to present the
data in a graphical way and record the values of all
the original data.
E.g.
The weights of 25 students
Stem (10 kg) Leaf (1 kg)
3
4
5
6
8
0
0
1
9
2 3 3 4 6 7 7 8 9
0 1 2 2 2 5 6 8
3 5 7
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(36)
 Example
C)
Stem-and-leaf Diagrams
1. Understanding Stem-and-leaf Diagrams
E.g.
ii. If we want to compare two groups of related data,
we can use back-to-back stem-and-leaf diagram.
The lifetimes (in hours) of 30 Brand A batteries and 30 Brand B batteries
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(37)
 Example
C)
Stem-and-leaf Diagrams
2. Drawing a Stem-and-leaf Diagram
i.
Check the range of the collected data and choose
the place values for the ‘stems’ and the ‘leaves’.
ii. Arrange the numbers in the stem from top to
bottom in an ascending order of magnitude.
iii. List each datum to the right of its corresponding
‘stem’.
iv. Arrange the data in the ‘leaves’ in ascending order.
 Index 12.4
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(38)
The following stem-and-leaf diagram shows the amount of daily
pocket money of students in Class A.
The amount of daily pocket money of students in Class A
Stem ($10)
0
1
2
3
4
5
Leaf ($1)
5
2
0
0
0
1
5
5
0
0
0
3
8
5
2 2 3 4 7
0 5 5 8 8
2 2 4 5
5
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(39)
(a) How many data are recorded in this stem-and-leaf diagram?
(b) It is known that Eric is one of the student
in Class A and he has the largest amount
of daily pocket money. Find the amount
of his daily pocket money.
(a) 30 data are recorded in the stem-and-leaf diagram.
(b) The amount of Eric’s daily pocket money is $55.
 Key Concept 12.4.5
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(40)
The areas (in square feet) of the homes of 20 students
from F.1A are shown below.
310 430 400 882 790 620 325 622 450 390
730 395 345 560 560 515 481 385 450 390
Using 100 sq. ft. as the stem and
1 sq. ft. as the leaf, construct a
stem-and-leaf diagram to present
the above data.
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(41)
 Back to Question
Areas of Homes of 20 Students from F.1A
Stem (100 sq.ft.)
Leaf (1 sq.ft.)
3
10 25 45 85 90 90 95
4
00 30 50 50 81
5
15 60 60
6
20 22
7
30 90
8
82
Fulfill Exercise Objective
 Construct a stem-and-leaf diagram.
 Key Concept 12.4.7
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(42)
The results of the IQ test for 2 groups of students A and
B are as follows:
Group A
Group B
81
103
119
86
100
93
102
113
117
85
98
115
112
102
100
114
120
126
121
127
118
114
120
115
112
121
88
90
101
123
106
107
(a) Construct a back-to-back stem-and-leaf diagram to
present the IQ of these two groups of students.
(b) If the IQ of a student is 120 or above, then he/she is
considered as a gifted student.Which group, A or B,
has more gifted students?
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(43)
 Back to Question
(a)
IQ of two groups of students
Group B
Group A
Leaf (Units digits) Stem (Tens digits) Leaf (Units digits)
3
7 6 2 2 1 0 0
8 5 4 4 3 2
3 0
8
9
10
11
12
1
0
3
2
0
5 6 8
8
5 7 9
1 1 6 7
(b) From the diagram in (a), there are more students in group A
whose IQ are 120 or above.
∴ Group A has more gifted students.
Fulfill Exercise Objective
 Construct/Interpret a back-to-back stem-and-leaf diagram.
 Key Concept 12.4.6
Index
12.4 Presentation and Analysis of Discrete Data
Scatter Diagrams
1. Understanding Scatter Diagrams
i. A scatter diagram is appropriate to show whether
two variables have close relationship with each other.
E.g.
Incomes and expenditures of 15 families
Expenditure ($)
D)
1B_Ch12(44)
Income ($)
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(45)
 Example
D)
Scatter Diagrams
1. Understanding Scatter Diagrams
ii. In general, the two variables x and y may relate in
different ways.
values of x increase,
values of y increase
values of x increase,
values of y decrease
two variables do not
have a clear relationship
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(46)
 Example
D)
Scatter Diagrams
2. Drawing a Scatter Diagram
i.
Indicate clearly on the x-axis and y-axis the
variable that each axis represents.
ii. Scales, values and units should be shown clearly
on the two axes.
iii. Represent the corresponding values of the two
variables on the rectangular coordinate plane using
a point ‘‧’ or ‘x’.
iv. Give a title to the scatter diagram.
 Index 12.4
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(47)
The heights of fathers and their sons are shown in the scatter
diagram.
Heights of fathers and their sons
195
Sons' height (cm)
190
185
180
175
170
165
160
155
140
150
160
170
180
190
200
Fathers' height (cm)
Do you think there is a relationship between the heights of
fathers and their sons?
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(48)
 Back to Question
Yes, there is a correlation between the heights of fathers and the
heights of their sons.
From the scatter diagram, it can be seen that:
the taller the father is, the taller his son will be.
 Key Concept 12.4.8
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(49)
A group of 10 students studied last
night for their dictation test today.
The table below shows the time that
each student spent on studying and
the number of mistakes that they
made in today’s dictation test.
Student
Time spent on studying (min)
No. of mistakes
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(50)
(a) Draw a scatter diagram to show the relationship
between the time spent on studying by the 10
students last night and the number of mistakes they
make in the dictation test today.
(b) According to the scatter diagram obtained
in (a), do you think there is a relationship
between the time that a student spent on
studying and the number of mistakes that
he makes in the dictation test?
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(51)
 Back to Question
(a) The required scatter diagram is:
Number of mistakes
Distribution of time spent on studying and number of
mistakes made in the dictation test
Fulfill Exercise Objective
Time spent on studying (min)
 Construct/Interpret a
scatter diagram.
(b) From the scatter diagram in (a), it can be seen that:
the more time a student spent on studying for the dictation
test, the fewer mistakes he/she makes.
 Key Concept 12.4.9
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(52)
 Example
E)
Choosing Suitable Statistical Graphs to Present Data
‧
There are many different types of statistical graphs.
The one that should be chosen to present the collected
data depends on the nature and the number of data, the
purpose of the survey, the points to be emphasized, etc.
 Index 12.4
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(53)
1. There were 5 major spendings for a certain company last
year.We can show the relationship between each spending
and the total spending by using a pie chart.
Major spendings for a company last year
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(54)
2. We can show the change in number of students in a certain
secondary school over the last 6 years by using a brokenline graph.
Number of students
Number of students in a secondary school
Year
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(55)
3. We can show the relationship between the time spent by 30
students in doing their project and the marks they obtained
from the project by using a scatter diagram.
Mark
Time spent and marks obtained
from the project
Time spent (hour)
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(56)
4. In one of the Home Ownership Schemes provided by the
government, 10 different sizes of flats are available. The
distribution of the areas of these flats can be shown in a
stem-and-leaf diagram.
Areas of flats
Stem (100 sq.ft.)
Leaf (1 sq.ft.)
4
15 24
5
30 25 70 89
6
40 48 90
7
28
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(57)
In September 1999, the Walt Disney
Company decided to build a theme
park in Hong Kong.The admission
fee of the theme park would be
around $250 to $350. Some citizens
were interviewed to ask their views
on the admission fees. The
following results were obtained.
Opinion
Number of citizens
Expensive
217
Moderate
285
Cheap
16
Index
12.4 Presentation and Analysis of Discrete Data
1B_Ch12(58)
 Back to Table
Which statistical graph is most suitable to present the above
data, and at the same time
(a) shows clearly the number of citizens in each category.
(b) shows the number of citizens in each category as a
percentage of the total number.
(a) A bar chart can best present the above data.
(b) A pie chart can best present the above data.
Fulfill Exercise Objective
 Choose suitable statistical diagrams to present data.
 Key Concept 12.4.10
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(59)
Misuse of Statistical Diagrams
‧
Statistical diagrams are sometimes used deliberately
to exaggerate or conceal the truth, and to mislead the
readers.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(60)
 Example
What should we be careful when we are reading statistical
diagrams?
‧ Check whether the scales on the two axes have been
drawn correctly.
‧ Check whether the sizes of the groups have been distorted
or exaggerated in such a way to mislead people.
‧ The items of two statistical graphs cannot be compared
by the sizes of the angles in the graphs alone.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(61)
The following graph is a bar chart shown in the advertisement
of the Hurryson Telecommunications Company.
Charge per minute ($)
Charges on long-distance calls
Telecommunications Company
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(62)
 Back to Graph
(a) Measure the lengths of the bars of HK United and
Hurryson, express the length of the bar of Hurryson
Telecommunications Company as a fraction of that
of HK United.
(b) Now express the actual charges of Hurryson as a
fraction of HK United and compare this result with
that obtained in (a). Do you agree that this bar chart
is misleading? Explain your answer.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(63)
 Back to Question
1
(a) The length of the bar for Hurryson is
that of HK United.
5
(b) Actual charge per minute of HK United = $3.2
Actual charge per minute of Hurryson = $3
$3 15

The required fraction =
$3.2 16
15 1
Since  , the bar chart has a misleading effect.
16 5
Fulfill Exercise Objective
 Questions on statistical diagrams in which the scales
on the axes are not correctly drawn.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(64)
Monthly salary ($)
The Money Commercial College used the following
diagram to show the highest monthly salary of their fresh
graduates in the years 2004 and 2005.
Year
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(65)
(a) Find the areas of the two triangles A and B in the
statistical diagram shown above. Express the area
of B as a multiple of the area of A.
 Soln
(b) Find out, from the diagram, the actual
highest monthly salaries in the two
years. Express the one in 2005 as a
multiple of that in 2004.
 Soln
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(66)
 Back to Question
(a) Suppose each small square in the figure has a side of 1 unit:
1
16  30 sq. units
2
= 240 sq. units
Area of triangle B =
1
Area of triangle A =  8 15 sq. units
2
= 60 sq. units
∴ The required multiple =
240
4
60
Thus, the area of B is 4 times that of A.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(67)
 Back to Question
(b) From the diagram,
the highest monthly salary in 2005 = $12 000
the highest monthly salary in 2004 = $6 000
∴ The required multiple =
∴
$12 000
2
$6 000
The highest monthly salary in
2005 was 2 times that in 2004.
Fulfill Exercise Objective
 Questions on statistical
diagrams in which the
sizes of figures are
distorted or
exaggerated.
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(68)
Fig. A below shows the profits of ABC company from 2000 to
2004. In order to show the shareholders that the company’s
profit has increased a lot since 1990. The managing director of
the company added the profit of the company in 1990 to the
Profit of ABC company from
graph (Fig. B).
1990 to 2004
Profit ($ million)
Profit ($ million)
Profit of ABC company from
2000 to 2004
Fig. A
Year
Year
Fig. B
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(69)
(a) As compared with Fig. A, does
Fig. B give the readers an
impression that the company’s
profit increases rapidly?
(b) Do you think that the managing director is
misleading the readers in Fig. B? Why?
Index
12.5 Misuse of Statistical Graphs
1B_Ch12(70)
 Back to Question
(a) Yes, Fig. B gives the readers an impression that the
company’s profit increases rapidly.
(b) Yes, the managing director is misleading the readers in
Fig. B. Because the profits in the years 1991 to 1999 are
not shown, people may be misled to think that the profit
increases rapidly from 1990 to 2000.
Fulfill Exercise Objective
 Questions on statistical diagrams showing only
a part of data.
 Key Concept 12.5.1
Index