Statistics(STAT100 )
Dr.Ammar Alsinai
Current address
College of Engineering and Information Technology OnizahColleges
email and contact number
aalsinae@oc.edu.sa.; 0550651591
September 1, 2025
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Basic Course Information
• Course code: STAT100
• Course name: Statistics
• Level: B.Sc.
• Course Credit: 3 credits
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Assessment
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Lectures Reference
Introductory Statistics, 8th edition, by Prem S. Mann, ©2011, John Wiley Sons
publishing, ISBN: 978-0-470-50583-0
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Course Syllabus
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HOW TO SUCCESS IN STAT100 with Excellent Grade?
• Come to every class and in time
• Bring you learning material, pen, Notebook, and Calculator always with you
• practice, practice, practice!
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Statistics:
Statistics is a group of methods used to collect, analyze, present, and interpret data and
to make decisions.
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Types of Statistics
• Descriptive statistics consists of methods for organizing, displaying, and describing
data by using tables, graphs, and summary measures.
• Inferential Statistics Inferential statistics consists of methods that use sample results
to help make decisions or predictions about a population.
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data set,element, observation:
Suppose we have information on the test scores of students enrolled in a statistics class.
In statistical terminology, the whole set of numbers that represents the scores of students
is called a dataset, the name of each student is called an element, and the score of each
student is called an observation
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population; sample :
In statistics, the collection of all elements of interest is called apopulation. The selection
of a few elements from this population is called a sample
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Sample
Sample A portion of the population selected for study is referred to as a sample.
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Population or Target Population
Population or Target Population A population consists of all elements—individuals, items,
or objects—whose characteristics are being studied. The population that is being studied
is also called the target population.
2-The 2009 gross sales of all companies in Onizah City
2. The prices of all houses in Onizah
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Census and Sample Survey A survey:
Census and Sample Survey A survey that includes every member of the population is
called a census. The technique of collecting information from a portion of the population
is called a sample survey
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Representative Sample:
Definition Representative Sample A sample that represents the characteristics of the
population as closely as possible is called a representative sample.
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Random Sample:
Definition Random Sample A sample drawn in such a way that each element of the
population has a chance of being selected is called a random sample. If all samples of the
same size selected from a population have the same chance of being selected, we call it
simple random sampling. Such a sample is called a simple random sample.
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Element or Member:
Element or Member An element or member of a sample or population is a specific subject
or object (for example, a person, firm, item, state, or country) about which the
information is collected.
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Variable :
A variable is a characteristic under study that assumes different values for different
elements. In contrast to a variable, the value of a constant is fixed.
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Observation or Measurement:
observation or measurementThe value of a variable for an element is called an
observation or measurement.
Data Set A data set is a collection of observations on one or more variables
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Types of Variables:
Quantitative Variable A variable that can be measured numerically is called a quantitative
variable. The data collected on a quantitative variable are called quantitative data.
Discrete Variable A variable whose values are countable is called a discrete variable. In
other words, a discrete variable can assume only certain values with no intermediate
values.
Continuous Variable A variable that can assume any numerical value over a certain
interval or intervals is called a continuous variable
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Types of Variables:
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Statistics
1- Statistics and types of Statistics :
What is statistics ?
Definition : statistics is the science of collecting , analyzing , presenting , interpreting data, as
well as of making decisions based on such analyses.
Figure 1
Definitions
( a ) Descriptive statistics: consists of methods for organizing, displaying, and describing data
by using tables, graphs and summary measures.
( b ) Inferential statistics: consists of methods that use sample results to help make decisions
about a population.
Figure 2
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Data
Definition :data set is the collection of observed values of the statistical variable .
types of data
Figure 3
Definitions
1- Qualitative data :
Data generated by Qualitative variable.
2- Quantitative data :
Data generated by a quantitative variable
Organizing and Graphing Qualitative data
Data sets are Organized into tables and displayed using graphs . First we discuss of raw data .
definition : Raw data — Data recorded in the sequence in which they are collected and before
are ranked .
EXAMPLE :1
A sample of 30 employees from large companies was selected, and these employees were asked
how stressful their jobs were. The responses of these employees are recorded below, where very
represents very stressful, somewhat means somewhat stressful, and none stands for not stressful
at all.
Somewhat none somewhat very very none Very somewhat somewhat very somewhat somewhat
very somewhat none very none somewhat somewhat very somewhat somewhat very none somewhat very very somewhat none somewhat
Construct a frequency distribution table for these data?
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Figure 4
Relative Frequency and Percentage Distribution
Relative F requency of category =
F requency of that category
Sum of all F requencies
P ercentage = (Relative F requency).100
Example (2)
Determine the relative Frequency and percentage distribution for the data in example (1).
solution
Figure 5
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Bar Graphs
Figure 6: Bar graph for the frequency distribution of Table 2.4. Very Somewhat None
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