REGRESSION ANALYSIS
EGRESSION ANALYSIS
1
INTRODUCTION
Regression analysis attempts to establish the nature of the relationship
between variables that are related causally, that is, to study the functional
relationship between the variables and thereby pro

Methods of sampling
Random
Simple random
Stratified
Cluster
Quasi-random
Systematic
Non-random
Quota
Fig. 1
Fig. 1 shows the some of the different methods of sampling belonging to the three categories.
For random sampling, a sampling frame is not only a p

You may recall from lecture one that there are several good reasons for taking a
sample instead of conducting a census, for example, to save time, money, etc. Also, in
the same lecture we said that if a researcher is using data gathered on a group to reac

QUESTIONNAIRE DESIGN
Initial considerations
Type of information required
Type/nature of respondents
Type and method by which survey is to be administered
Question content
Question phrasing
Relevance of a question
Clarity of a question
Avoid ambiguous,

PROBABILITY THEORY
In the world of Statistics, the word that can most suitably replace probability
would be ' chance '. Probability can be considered as a measure of likelihood of an event
occurring. There are two ways of assigning numerical values to pro

Probability Distribution:
A probability distribution is similar to the frequency distribution of a quantitative
population because both provide a long-run frequency for outcomes. In other words, a
probability distribution is listing of all the possible va

PRESENTATION OF DATA
1.1
INTRODUCTION
Once data has been collected, it has to be classified and organised in such
a way that it becomes easily readable and interpretable, that is, converted to
information. Before the calculation of descriptive statistics,

The Poisson distribution
The Poisson distribution is, like the Binomial distribution, a theoretical discrete
distribution that is used to calculate the probability that a random event occurs a given number of
times. Given a Poisson variable X, the values

CORRELATION ANALYSIS
Correlation is another way of assessing the relationship between variables.
To be more precise, it measures the extent of correspondence between the
ordering of two random variables. There is a large amount of resemblance
between regr

The Normal distribution
The Normal distribution is a continuous theoretical probability distribution and, probably,
the most important distribution in Statistics. Its name is justified by the fact that it is suitable to
almost any variable in normal real-

Measures of Location for Ungrouped or Raw Data:
Measures of location give information about location in a group of numbers or
data. The measures of location presented in this lecture note for ungrouped
(raw) data are the mean, the median, and the mode.
Ar

MEASUREMENT SCALES
EASUREMENT SCALES
INTRODUCTION
Variables differ in how well they can be measured, that is, in how much
measurable information their measurement scale can provide. There is obviously
some measurement error involved in every measurement,

Introduction:
Decision makers make better decisions when they use all
available information in an effective and meaningful way. The
primary role of statistics is to to provide decision makers with
methods for obtaining and analyzing information to help ma

Frequency Distribution:
The easiest method of organizing data is a frequency distribution, which
converts raw data into a meaningful pattern for statistical analysis.
The following are the steps of constructing a frequency distribution:
1. Specify the num

ESTIMATION
STIMATION
1
INTRODUCTION
Estimation is the statistical process of finding an approximate value for a
population parameter. A population parameter is a characteristic of the
distribution of a population such as the population mean, the populatio

DESCRIPTIVE STATISTICS
ESCRIPTIVE STATISTICS
1
INTRODUCTION
Numbers and quantification offer us a very special language which
enables us to express ourselves in exact terms. This language is called
Mathematics. We will now learn the basic rules of Mathema

The Chi-squared distribution
If a normal variable X, having mean and variance 2 , is standardised, the new variable Z has
a mean 0 and variance 1. When this standardised variable is squared, it is said to follow a chi-squared
distribution with one degree

The Binomial distribution
The binomial distribution is a theoretical (regular) discrete probability distribution that is mainly
used to calculate probabilities in experiments where there can either be
1.
2.
Two possible outcomes or
Several outcomes classi

Approaches of Assigning Probabilities:
There are three approaches of assigning probabilities, as follows:
1. Classical Approach:
Classical probability is predicated on the assumption that the outcomes of an
experiment are equally likely to happen. The cla

Uniform (or Rectangular) Distribution:
Among the continuous probability distribution, the uniform distribution is the simplest
one of all. The following figure shows an example of a uniform distribution. In a
uniform distribution, the area under the curve

STATISTICAL INFERENCE
1
INTRODUCTION
Statistical inference is that branch of Statistics in which one typically
makes a statement about a population based upon the results of a sample. In onesample testing, we essentially have to verify whether a populatio