22. Категорийн өгөгдлийн график:
Олон хэмжээст өгөгдөл
Категорийн өгөгдөл
Өгөгдлийн график
Өгөгдлийг
хүснэгтлэх
Хураангуй хүснэгт
Дугуй диаграмм
CD
S avings
B onds
S toc k s
0
10
20
30
40
50
Тэгш
өнцөгт
диаграмм
Парето диаграмм
45
12 0
40
10 0
35
30
80
25
60
20
15
40
10
20
5
0
0
S toc k s
B ond s
S a vings
CD
26. Хоёр хэмжээст категорийн
өгөгдлийн хүснэгт ба график
Санамсаргүй үзэгдлийн хүснэгт: хөрөнгө оруулалт мянган
доллараар
Investment
Category
Investor A
Investor B
Investor C
Total
Stocks
Bonds
CD
Savings
46.5
32
15.5
16
55
44
20
28
27.5
19
13.5
7
129
95
49
51
Total
110
147
67
324
27. Хоёр хэмжээст категорийн
өгөгдлийн хүснэгт ба график
Хоёр талт диаграмм
Comparing Investors
S avings
CD
B onds
S toc k s
0
10
Inves tor A
20
30
Inves tor B
40
50
Inves tor C
60
46. Five Number Summary
The weekly TV viewing times (in hours).
25
34
41 27
26 32
32
38
43 66
16 30
35
38
31 15
30 20
5
21
The array of the above data is given below:
5
15 16 20 21 25 26 27 30 30
31 32 32 34 35 37 38 41 43 66
47. Five Number Summary
LOCATION of Q1 ;
1(20 + 1)
4
th obs. in the data = 5.25th obs.
VALUE of Q1 ; 5th obs. + 0.25{6th obs. - 5th obs.} = 21 + 0.25{25 - 21} = 22.0 Hrs
LOCATION of Q 2 ;
VALUE of Q2
2(20 + 1)
4
th obs. in the data = 10.50 th obs.
;10 th obs. + 0.50{11th obs. - 10th obs.} = 30 + 0.50{31 - 30} = 30.5 Hrs
LOCATION of Q 3 ;
3(20 + 1)
4
th obs. in the data = 15.75th obs.
VALUE of Q 3 ; 15th obs + 0.75 {16th obs - 15th obs} = 35 + 0.75{37 - 35} = 36.5 Hrs
Minimum value=5.0
Maximum value=66.0
48. Box and Whisker Diagram
A box and whisker diagram or box-plot is a
graphical mean for displaying the five number
summary of a set of data. In a box-plot the first
quartile is placed at the lower hinge and the
third quartile is placed at the upper hinge. The
median is placed in between these two hinges.
The two lines emanating from the box are
called whiskers. The box and whisker diagram
was introduced by Professor Jhon W. Tukey.
49. Construction of Box-Plot Max
Valu
1.
2.
3.
4.
Start the box from Q1 and end at
Q3
Within the box draw a line to
represent Q2
Draw lower whisker to Min. Value
up to Q1
Draw upper Whisker from Q3 up
to Max. Value
e
Q3
Q2
Q1
Min
Value
51. 70
Interpretation of Box-Plot
Box-Whisker Plot is useful to identify
60
•Maximum and Minimum Values in the data
•Median of the data
50
•IQR=Q3-Q1,
Lengthy box indicates more variability in the data
•Shape of the data From Position of line within box
Line At the center of the box----Symmetrical
skewed
Line above center of the box----Negatively
Line below center of the box----Positively Skewed
•Detection of Outliers in the data
40
30
20
52. Outliers
An outlier is the values that falls well outside the overall
pattern of the data. It might be
•
•
•
the result of a measurement or recording error,
a member from a different population,
simply an unusual extreme value.
An extreme value needs not to be an outliers; it might,
instead, be an indication of skewness.
54. 80
Identification of the Outliers
70
1. The values that lie within inner
fences are normal values
2. The values that lie outside inner
fences but inside outer fences
are
possible/suspected/mild
outliers
3. The values that lie outside outer
fences are sure outliers
60
Only
66 is a
mild
outlier
Plot each suspected outliers with an asterisk
and each sure outliers with an hollow dot.
50
40
30
20
10
0
*
55. Uses of Box and Whisker Diagram
Box plots are
especially suitable for
comparing two or more
data sets. In such a
situation the box plots
are constructed on the
same scale.
Male
Female
56. Standardized Variable
A variable that has mean “0” and Variance “1” is
called standardized variable
Values of standardized variable are called standard
scores
Values of standard variable i.e standard scores are
unit-less
Construction
Variable − Mean of Variable
Z=
Standard Deviation of Variable
57. Standardized Variable
X
( X − X )2
3
25
-1.3624 1.8561
6
4
-0.5450 0.2970
Z
(Z − Z ) 2
11
9
0.81741 0.6682
12
16
1.0899
32
54
0
1.1879
4.009
Variable Z has mean “0” and
X
2
Sx
∑X
=
=
32
=8
4
n
54
=
=13.5
4
Z=
X− X X−8
=
Sx
3.67
∑Z
Z =
2
Sz
=0
n
4.009
=
≅1
4
variance “1” so Z is a standard
variable.
X − X 11 − 8
Z=
=
= 0.8174
3.67
Standard Score at X=11 is Sx
58. The Empirical Rule
68.26%
X ± 1S contains about 68.26% of values
X
X ± 1S
X ± 2S contains about 95.45% of values
95.45%
X ± 2S
99.73%
X ± 3S
X ± 3S contains about 99.73% of values
59. Measures of
Skewness
A distribution in which the values
equidistant from the centre have
equal frequencies is defined to be
symmetrical and any departure from
symmetry is called skewness.
1. Length of Right Tail = Length of Left
Tail
2. Mean = Median = Mode
3. Sk=0
a) Sk=(Mean-Mode)/SD
b) Sk=(Q3-2Q2+Q1)/(Q3-Q1)
60. Measures of Skewness
A distribution is positively skewed, if the
observations tend to concentrate more at
the lower end of the possible values of the
variable than the upper end. A positively
skewed frequency curve has a longer tail
on the right hand side
1. Length of Right Tail > Length of Left
Tail
2. Mean > Median > Mode
3. SK>0
61. Measures of Skewness
A distribution is negatively skewed, if
the observations tend to concentrate
more at the upper end of the possible
values of the variable than the lower
end. A negatively skewed frequency
curve has a longer tail on the left side.
1. Length of Right Tail < Length of Left
Tail
2. Mean < Median < Mode
3. SK< 0
62. Measures of Kurtosis
•
•
•
The Kurtosis is the degree of peakedness or flatness of a
unimodal (single humped) distribution,
When the values of a variable are highly concentrated around
the mode, the peak of the curve becomes relatively high; the
curve is Leptokurtic.
When the values of a variable have low concentration
around the mode, the peak of the curve becomes relatively
flat;curve is Platykurtic.
A curve, which is neither very peaked nor very flat-toped, it
is taken as a basis for comparison, is called
Mesokurtic/Normal.
64. Measures of Kurtosis
Coefficient of Kurtosis=
n ∑ ( X-X )
4
2 2
( X-X )
∑
1. If Coefficient of Kurtosis > 3 ----------------- Leptokurtic.
2. If Coefficient of Kurtosis = 3 ----------------- Mesokurtic.
3. If Coefficient of Kurtosis < 3 ----------------- is Platykurtic.
65. Histograms and Bar Charts
To help students distinguish
the
histogram from the simple bar chart,
for the data here is the example from
page 39 of the Histograms Chapter
(Chapter 3) which also mentions the
advantage of the histogram for larger
data sets.
66. Histogram, Box Plot, and CDF
To compare and contrast these three
basic exploratory charts, here is the
example from page 83 of Chapter 4
on Landmark Summaries.
67. Probability Trees
Probability is less
mysterious to
students when
there is a visual
framework, as
shown here in the
example from page
144 of Chapter 6.
68. Bivariate Data Examples
Relationships and regression are powerful
business concepts. Here are a couple of the
examples from Chapter 11 on Bivariate
Data (pages 295 and 308).
69. Magazine Ads and Multiple Regression
The cost of advertising can be explained,
in part, by magazine characteristics such
as audience size and income level in this
example that is used to illustrate the
power of multiple regression in business,
from Chapter 12.
70. Excel Guide
The Excel Guide goes step-by-step
through, chapter by chapter, to show
students how Excel can be used to obtain
statistical results. Here is the scatterplot
example from page 82 of the Excel Guide.