Matakuliah
Tahun
Versi
: I0134 – Metoda Statistika
: 2005
: Revisi
Pertemuan 01
Data dan Statistika
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Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Mahasiswa dapat memberikan definisi
istilah-istilah statistika, pengumpulan data
dan skala pengukuran
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Outline Materi
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•
Data
Statistika
Populasi dan Sampel
Skala pengukuran
Pengumpulan data
Pengolahan dan Penyajian data
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Introduction and Descriptive Statistics
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Using Statistics
Percentiles and Quartiles
Measures of Central Tendency
Measures of Variability
Grouped Data and the Histogram
Skewness and Kurtosis
Relations between the Mean and Standard
Deviation
Methods of Displaying Data
Exploratory Data Analysis
Using the Computer
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1-1.
Using Statistics (Two
Categories)
• Descriptive Statistics
– Collect
– Organize
– Summarize
– Display
– Analyze
Without generalization
• Inferential Statistics
- Predict and forecast
values of population
parameters
- Test hypotheses
about values of
population
parameters
- Make decisions
On basis of limited and
incomplete sample
information
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Types of Data - Two Types

Qualitative Categorical or
Nominal: Examples
are– Color
– Gender
– Nationality
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Quantitative Measurable or
Countable:
Examples are– Temperatures
– Salaries
– Number of points
scored on a 100 point
exam
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Scales of Measurement
• Nominal Scale - groups or classes
–Gender
• Ordinal Scale - order matters
–Ranks
• Interval Scale - difference or distance
matters
–Temperatures
• Ratio Scale - Ratio matters
–Salaries
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Samples and Populations
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A population consists of the set of all
measurements in which the
investigator is interested.
A sample is a subset of the
measurements selected from the
population.
A census is a complete enumeration
of every item in a population.
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Simple Random Sample
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Sampling from the population is
often done randomly, such that every
possible sample of equal size (n) will
have an equal chance of being
selected.
A sample selected in this way is
called a simple random sample or
just a random sample.
A random sample allows chance to
determine its elements.
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Samples and Populations
Population (N)
Sample (n)
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Why Sample?
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Census of a
population may
be:
– Impossible
– Impractical
– Too costly
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1-2 Percentiles and Quartiles
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Given any set of numerical
observations, order them according to
magnitude.
The Pth percentile in the ordered set is
that value below which lie P% (P
percent) of the observations in the set.
The position of the Pth percentile is
given by (n + 1)P/100, where n is the
number of observations in the set.
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Example 1-2 (1) Raw Data
A large department store
collects data on sales made by
each of of its salespeople. The
number of sales made on a
given day by each of 20
salespeople is shown on the next
slide. Also, the data has been
sorted in magnitude.
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Selamat Belajar Semoga Sukses.
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