Statistics can be summarized as the collection, organization, presentation, analysis, and interpretation of data. Descriptive statistics aims to summarize or describe data without inferring anything beyond what is shown by the data itself. It answers questions about who, what, how, etc. based on the data. The roles of descriptive statistics include determining what data to collect, how much to collect, how to organize it, and how to interpret it.

1. Statistics
Chapter 1

2. Statistics
• status, census
• as a science
“ a collection, organization,
presentation, analysis, and
interpretation of data”
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3. Descriptive Statistics
• Includes anything Answers questions such
done to data which is as
designed to Who…
summarize or What…
describes, without
going any further, that How… performed better in
Who
What are the highest and
the entrance examination?
is without attempting lowest scores obtained
What is the most
to infer anything that by students in thein
populated school test?
goes beyond the data Metro Manila?
How many students are
themselves. interested to take
Statistics online?
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4. What are the Roles and Principal
Objectives of Descriptive Statistics
as a Scientific Discipline
• What kind of data to be collected?
• How much data need to be collected?
• How should we organize the data?
• How should we interpret the data?
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5. Most Pinoys Believe in Love at First Sight
(Source: Philippine Daily Inquirer, February 15, 2002)
According to the survey made by the Social Weather Stations
(SWS) in November, MAJORITY of Filipinos believe in love at first sight
and say each person has only one true love. Belief in love at first sight is
higher among middle-aged and older Filipinos compared to younger
ones, and higher among Filipinos with less education. Compared to a
February 2000 Gallup poll in the United States, the SWS survey found
that more Filipinos believe in love at first sight (72% compared to 52%
among Americans), have experienced falling in love at first sight (64%
compared to 40% among Americans), and believe in one true love (84%
compared to 74% among Americans). When asked about their past
relations, SWS found that 70% of Filipino men have experienced falling
in love at first sight, as compared to only 58% of Filipino women. Sixty-
seven percent (67%) of married Filipinos are more likely to say they
have experienced falling in love at first sight, compared to 54% of single
Filipinos.
The SWS said it surveyed 1,200 adults. The results have a 3%
margin of error.
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6. Terms Used in
Statistics Population Parameter
Population
- is the set of measurements
corresponding to the entire collection We may wish indicated
not
We maytelevision
A typical wish to
to
of units about which the information is network surveys uses a
draw conclusions
conclusion
sought. sample of 2000
- is the group of objects about which about the recovery
how Metro
conclusions are to be drawn.
households and the
Manilans vote in the
rate ofare used to form
results 4000 college
Parameter
coming presidential
students by studying
conclusions about the
- is any numerical value which election by 300
a sample ofall
population of studying
describes a population 26,000,000 of 1000
a sample households
students from the
in the country. this
persons from
population.
Sample
- the set of measurement that are population.
actually collected in the course of the
investigation.
- is the portion of the subset of objects
Sample
drawn from the population.
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7. Classification of Data
Qualitative Variables QUALITATIVE
1) color of - measure a quality or
the eye are attributes which cannot be
characteristics on each subjected to meaningful
1) color of the eye
2)individualof computers in a room
number or object, arithmetic.
3) position in an organization
3)distinguished by some
position in an organization
nonnumeric characteristics. 5) Rate of politician (e.g. excellent)
4) number of students enrolled in NEU 6) state of our forest
5) Rate of politician (e.g. excellent)
6) state of our forest QUANTITATIVE
7) temperature Variables City
Quantitative in Baguio arenumber of computers in a room
2) numerical in nature and
- measure a numerical therefore meaningful
4) number of students enrolled in NEU
8) amount of time to finisheach
quantity or amount on the test arithmetic can be done.
individual or object. 7) temperature in Baguio City
9) scores in exam
8) amount of time to finish the test
9) scores in exam
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8. QUANTITATIVE
2) number of computers in a room
- assume exact - assume the infinitely
many values corresponding to
values only. It can assume of students enrolled in NEU
4) number
only a finite or countable the point on a line interval in
7) temperature in Baguio Citya way that there are no
such
number of values. Decimals
gaps or interruptions. Decimals
have no meaning. 8) amount of time to finish the test
have meaning.
9) scores in exam
DISCRETE CONTINUOUS
2) number of computers in a room 7) temperature in Baguio City
4) number of students enrolled in
8) amount of time to finish the test
NEU
9) scores in exam
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9. Scales of Measurement
-categorical
NOMINAL ORDINAL
-
INTERVAL RATIO
names, labels,
or categorized
1) The different only
1) sizes of t-shirts
students’ (e.g. small) do
1) honor of
-numbers students 1) length of movies
organization not mean
2) The survey 2) rating of
anything 2) ranking in a 2) number of votes
politician (e.g.
responses of yes, contest
poor)
no or undecided
-numerical -numerical
-categorical
-numbers are -numbers are
-categorical -numbers are used
used to label used
-names, labels, -differences
and categorize and rank -differences
between data between data
only -differences values are
between data values are
-numbers don’t meaningful meaningful
mean anything values are
meaningless -no zero -have zero
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10. ACTIVITY NO. 2
Prof. Amelia F. Asaytono
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11. Activity No. 1b
A restaurant wants to get feedback from its 1000 customer on the quality of food and
services it offers. Below is a sample of the survey questionnaire that they distribute to
their 100 customers.
Using the sample survey, identify at least five variables that you can classify as
QUANTITATIVE or QUALITATIVE. For QUALITATIVE VARIABLE, determine if it is
NOMINAL or ORDINAL. For QUANTITATIVE VARIABLE, determine if it is RATIO or
INTERVAL and DISCRETE or CONTINUOUS.
Name: Quality of Food
________________________________ _____VS _____S _____US
Age: _____________ Gender: Serving Size
_________________ _____VS _____S _____US
Nutritional Orientation Services
____ Vegetarian ____ Non-vegetarian _____VS _____S _____US
How often do you go to this restaurant?
____ once a week VS - Very Satisfactory
____ twice a week S - Satisfactory
____ more than twice a week US - Unsatisfactory
____ others
What type of orders do you usually Remarks/Comments/Suggestions:
take? __________________________
____ solo meals ____ group meals __________________________
____ combo meals ____ ala carte
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12. References
High School Statistics by Campeña
Basic Statistics with Probability by
Hernandez
Elementary Statistics by Blay
Introduction to Probability and
Statistics by Calingasa
PowerPoint Lay-out
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