Download - Statistik Deskriptif Cara Penyajian Data
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