Upload
riezea
View
18.935
Download
6
Embed Size (px)
DESCRIPTION
Statistika merupakan bidang ilmu yang mempelajari tentang ilmu statistik di mana dilihat dari analisis terdiri dari dari jenis yaitu statistik deskriptif dan statistik inferensia. Statistik deskriptif merupakan statistik dasar yang mempelajari bagaimana mengolah data, menganalisis, tabulasi,dan penyajiannya.
Citation preview
STATISTIK DESKRIPTIF
Isi:
Pengenalan tipe data dan cara penyajian data
Basic Business Statistics: Concepts & Applications
Presenting Data in Tables & Charts
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
Ordered Array
• 1. Organizes Data to Focus on Major Features
• 2. Data Placed in Rank Order – Smallest to Largest
• 3. Data in Raw Form (as Collected)– 24, 26, 24, 21, 27, 27, 30, 41, 32, 38
• 4. Data in Ordered Array– 21, 24, 24, 26, 27, 27, 30, 32, 38, 41
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
Stem-and-Leaf Display
• 1. Divide Each Observation into Stem Value and Leaf Value– Stem Value Defines
Class
– Leaf Value Defines Frequency (Count)
2 144677
3 028
4 1
2. Data: 21, 24, 24, 26, 27, 27, 30, 32, 38, 41
26
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
Frequency Distribution Table
Raw Data: 24, 26, 24, 21, 27, 27, 30, 41, 32, 38
Class Frequency
15 but < 25 3
25 but < 35 5
35 but < 45 2
Frequency Distribution Table Steps
• 1. Determine Range
• 2. Select Number of Classes– Usually Between 5 & 15 Inclusive
• 3. Compute Class Intervals (Width)
• 4. Determine Class Boundaries (Limits)
• 5. Compute Class Midpoints
• 6. Count Observations & Assign to Classes
Frequency Distribution Table Example
Raw Data: 24, 26, 24, 21, 27, 27, 30, 41, 32, 38
Boundaries (Upper + Lower Boundaries) / 2
Width
Class Midpoint Frequency
15 but < 25 20 3
25 but < 35 30 5
35 but < 45 40 2
Relative Frequency & % Distribution Tables
Percentage Distribution
Relative Frequency Distribution
Class Prop.
15 but < 25 .3
25 but < 35 .5
35 but < 45 .2
Class %
15 but < 25 30.0
25 but < 35 50.0
35 but < 45 20.0
Cumulative Percentage Distribution Table
Percentage Less than Lower Class Boundary
Raw Data: 24, 26, 24, 21, 27, 27, 30, 41, 32, 38
Lower Class Boundary
30% + 50%
80% + 20%
Class CumulativePercentage
15 but < 25 0.0
25 but < 35 30.0
35 but < 45 80.0
45 but < 55 100.0
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
0
1
2
3
4
5
Histogram
Frequency
Relative Frequency
Percent
0 15 25 35 45 55
Lower Boundary
Bars Touch
Class Freq.15 but < 25 325 but < 35 535 but < 45 2
Count
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
0
1
2
3
4
5
Polygon
Midpoint
Fictitious Class
0 10 20 30 40 50 60
Class Freq.15 but < 25 325 but < 35 535 but < 45 2
Frequency
Relative Frequency
Percent
Count
Numerical Data Presentation
OrderedArray
OgivePolygonHisto-gram
FrequencyDistributions
NumericalData
Stem-&-LeafDisplay
0%
25%
50%
75%
100%
Cumulative % Polygon (Ogive)
Lower Boundary
Fictitious Class
0 15 25 35 45 55
Class Cum. %15 but < 25 0%25 but < 35 30%35 but < 45 80%45 but < 55 100%
Cumulative %
Errors in Presenting Data
• 1. Using ‘Chart Junk’
• 2. No Relative Basis in Comparing Data Batches
• 3. Compressing the Vertical Axis
• 4. No Zero Point on the Vertical Axis
‘Chart Junk’
Bad Presentation Good Presentation
1960: $1.00
1970: $1.60
1980: $3.10
1990: $3.80
Minimum Wage Minimum Wage
0
2
4
1960 1970 1980 1990
$
No Relative Basis
Good Presentation
A’s by Class A’s by Class
Bad Presentation
0
100
200
300
FR SO JR SR
Freq.
0%
10%
20%
30%
FR SO JR SR
%
Compressing Vertical Axis
Good Presentation
Quarterly Sales Quarterly Sales
Bad Presentation
0
25
50
Q1 Q2 Q3 Q4
$
0
100
200
Q1 Q2 Q3 Q4
$
No Zero Point on Vertical Axis
Good Presentation
Monthly Sales Monthly Sales
Bad Presentation
0
20
40
60
J M M J S N
$
36
39
42
45
J M M J S N
$
Categorical Data Presentation
ParetoDiagram
PieChart
CategoricalData
1 Variable
BarChart
SummaryTable
Summary Table
• 1. Lists Categories & No. Elements in Category
• 2. Obtained by Tallying Responses in Category
• 3. May Show Frequencies (Counts), % or Both
Row Is Category
Tally:|||| |||||||| ||||
Major CountAccounting 130Economics 20Management 50Total 200
Categorical Data Presentation
ParetoDiagram
PieChart
CategoricalData
1 Variable
BarChart
SummaryTable
0 50 100 150
Acct.
Econ.
Mgmt.
Bar Chart
Horizontal Bars for Categorical Variables
Bar Length Shows Frequency or %
1/2 to 1 Bar Width
Equal Bar Widths
Zero Point
Frequency
Major
Percent Used Also
Categorical Data Presentation
ParetoDiagram
PieChart
CategoricalData
1 Variable
BarChart
SummaryTable
Econ.10%
Mgmt.25%
Acct.65%
Pie Chart
• 1. Shows Breakdown of Total Quantity into Categories
• 2. Useful for Showing Relative Differences
• 3. Angle Size– (360°)(Percent)
Majors
(360°) (10%) = 36°
36°
Categorical Data Presentation
ParetoDiagram
PieChart
CategoricalData
1 Variable
BarChart
SummaryTable
0%
33%
67%
100%
Acct. Mgmt. Econ.
Pareto Diagram
Percent
Major
Descending Order
Cumulative Polygon (Ogive)
Equal Bar Widths
Vertical Bar Chart
Bar Midpoint
Always %
Thinking Challenge
•You’re an analyst for IRI. You want to show the market shares held by Windows program manufacturers in 1992. Construct a bar chart, pie chart, & dot chart to describe the data.
• Mfg. Mkt. Share (%)•Lotus 15•Microsoft 60•WordPerfect 10•Others 15