Pertemuan 01 Data dan Statistika Matakuliah : I0134 – Metoda Statistika Tahun : 2005 Versi : Revisi Pertemuan 01 Data dan Statistika

Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : Mahasiswa dapat memberikan definisi istilah-istilah statistika, pengumpulan data dan skala pengukuran

Pengolahan dan Penyajian data Outline Materi Data Statistika Populasi dan Sampel Skala pengukuran Pengumpulan data Pengolahan dan Penyajian data

Introduction and Descriptive Statistics 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

1-1. Using Statistics (Two Categories) Descriptive Statistics Collect Organize Summarize Display Analyze Inferential Statistics - Predict and forecast values of population parameters - Test hypotheses about values of population parameters - Make decisions Without generalization On basis of limited and incomplete sample information

Types of Data - Two Types Qualitative - Categorical or Nominal: Examples are- Color Gender Nationality Quantitative - Measurable or Countable: Examples are- Temperatures Salaries Number of points scored on a 100 point exam

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

Samples and Populations 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.

Simple Random Sample 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.

Samples and Populations Population (N) Sample (n)

Census of a population may be: Why Sample? Census of a population may be: Impossible Impractical Too costly

1-2 Percentiles and Quartiles 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.

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.

Selamat Belajar Semoga Sukses.