1. STATISTICS
Is study or scientific method of collecting,
organizing, processing, presenting, and
analyzing data and drawing a conclusion
according to the result of the data analysis

2. Data
 Is information obtained from the result of observation
or research
 The Singular form of data is DATUM
 Data can describe a situation, so that based on the
data we can draw a conclution
 According to the types, data can be divided into two :
Qualitative Data and Quantitative Data
 Qualitative Data : are data related to the category or
characteristic like Math, Biology, beautiful, danger, tin,
slim,etc
 Quantitative Data : are obtained from the result of
numerical recording ( in the form of figures)

3. The Process
 The acquired data are arranged
 Processed
 Presented then anayzed carefully , accurately and
according to the right theory
 Based on the data that have been analyzed, we can
draw a conclusion
 Several examples of conclusion :- The profil of a
teacher affects the degree of student’s
understanding, -Giving balanced diet to children
under five years old greatly affects their growth,-The
average age of students who have just entered grade
VII in junior high school in Indramayu is 13 years old

4. The ways of collecting Data
 Counting
 Measuring
 Recording data by tallies
We should know what kind of data to be
collected in order to get a
conclusion(answer) to the problem we
are coping with.

5. Suppose we want to know the influence of the
economic level of parents on the study result of
student. To answer the problem, we should collect
data that cover :
- number of students
- position of students in their family
- kind of parents’ occupation
- study result of students
- condition of students’ homes
- and so on

6. According to the sum of data:
Simple Data/ Single
Data Grouped Data
 The Mean :
 The number of rows
 Mode : The value (classes)
that appears most  High Quartil
frequently/ the value of
highest frequency  Low Quartil
 The median: Middle  Inter Quartil
value after being  The Interval
ordered
 Frequency Table
 The Range :The
highest- The lowest

7. Examples
# given that the scores of Math test are :
4,6,7,8,9,10,2,5,7,8,9,9,9,7,3
So, find :range, mean, median and mode !
Solution
- range = 9-2 = 7
- mean = ( 2+ 3+4+5+6+3.7+2.8+4.9+1.10 ) : 15 =
111 : 15 = 7.4
- median = 7
- mode = 7
sc 2 3 4 5 6 7 8 9 10
ore
f 1 1 1 1 1 3 2 4 1

8. Population & Sample
Population
 A population is any entire collection of people, animals, plants or things from which we may collect data. It is the
entire group we are interested in, which we wish to describe or draw conclusions about.
 In order to make any generalisations about a population, a sample, that is meant to be representative of the population,
is often studied. For each population there are many possible samples. A sample statistic gives information about a
corresponding population parameter. For example, the sample mean for a set of data would give information about the
overall population mean.
 It is important that the investigator carefully and completely defines the population before collecting the sample,
including a description of the members to be included.
 Example
The population for a study of infant health might be all children born in the UK in the 1980's. The sample might be all
babies born on 7th May in any of the years.
Sample
 A sample is a group of units selected from a larger group (the population). By studying the sample it is hoped to draw
valid conclusions about the larger group.
 A sample is generally selected for study because the population is too large to study in its entirety. The sample should
be representative of the general population. This is often best achieved by random sampling. Also, before collecting
the sample, it is important that the researcher carefully and completely defines the population, including a description
of the members to be included.
 Example
The population for a study of infant health might be all children born in the UK in the 1980's. The sample might be all
babies born on 7th May in any of the years.


9. Populasi Dan Sampel
 Populasi
Populasi adalah keseluruhan dari objek
penelitian
 Sampel
Sampel adalah bagian dari populasi
 Sampel yang baik adalah sampel yang
representatif, yaitu sampel yang dapat mewakili
populasinya. Agar representatif, maka
pengambilan sampel dari populasi harus
menggunakan teknik pengambilan sampel
(sampling) yang benar.