KENYA METHODIST
UNIVERSITY
MATH 130: BASIC STATISTICS
CONTENT
INTRODUCTION
Definition of terms
Data Variables
DATA COLLECTION
Surveying methods
Sampling methods
Importance and Limitations of Statistics
ORANIZING DATA
Graphical representation
Frequency distribution tables
MEASURES OF CENTRAL TENDENCY AND OF DISPERSION OF DATA.
Measures of Central tendency
Measure of dispersion of data
Mean and standard deviation of grouped data.
Coefficient of variation (C.V)
SKEWNESS AND KURTOSIS
Skewness
, Kurtosis
CORRELATION AND REGRESSION ANALYSIS
Correlation coefficient (r )
Linear regression
Coefficient of determination
ELEMENTARY PROBABILITY
Definition of probability
Mutually exclusive events
Independent events
Combined events
2
,PERMUTATIONS AND COMBINATION
Factorial notation
Permutations
Combinations
I INTRODUCTION
Definitions of terms
Statistics is the study of how to collect, organize analyze and interpret numerical information
(data).
The main divisions of statistics are;
Descriptive statistics – refers to the statistical methods of describing and organizing data
e.g mean, median, mode, range, variance and standard deviation.
Inferential statistics – refers to the methods of using a sample to obtain information about
a population or making conclusions about a population from the sample statistics.
It is therefore, important to remember that the main role of inferential statistics is to draw
conclusions about a population based on information obtained from a sample.
Population – refers to all measurements of interest.
For example the weights of all pineapples in a field.
Sample – is simply a representative part of the population. For example, 100 weights
of pineapples.
DATA VARIABLES
Qualitative variables – no numerical value can be assigned, e.g, the colour of the hair.
3
, Quantitative variables – have numerical values, e.g. the number of people in a Sunday service.
Quantitative variables can be either discrete or continuous.
discrete variable – is one which naturally inherently contains gaps between successive
observation e.g. the number of family members in a family (it is either 2, 3, 4 etc but not 3.5
countries, number of chairs, number of animals, etc.
continuous variable has the property that between any 2 observable value lies another
observable value.
continuous variable takes values along a continuum, i.e along a whole interval of values, e.g.
length, weight, height, temperature, speed, PH of a solution etc.
An essential attribute of a continuous variable is that unlike a discrete variable, it can never
be measured exactly.
II COLLECTION OF DATA
It may be very difficult and tedious to collect data as the population may have a number of
characteristics and may be you are interested in only one or two characteristics e.g. pineapples in
a field, required to estimate the mean weight of the pineapples.
Data may be obtained through the following methods:
a) Survey
The most common method of collection of data is through surveys which have to be conducted
very carefully otherwise, the results would be of no value. Survey consists of two parts:
Planning
You need to consider:
Nature of problem.
Objective and scope of enquiry
Source of information
Type of enquiry to be conducted
Accuracy desired.
Executing the plan - involves various steps to put the plans in operation.
4
UNIVERSITY
MATH 130: BASIC STATISTICS
CONTENT
INTRODUCTION
Definition of terms
Data Variables
DATA COLLECTION
Surveying methods
Sampling methods
Importance and Limitations of Statistics
ORANIZING DATA
Graphical representation
Frequency distribution tables
MEASURES OF CENTRAL TENDENCY AND OF DISPERSION OF DATA.
Measures of Central tendency
Measure of dispersion of data
Mean and standard deviation of grouped data.
Coefficient of variation (C.V)
SKEWNESS AND KURTOSIS
Skewness
, Kurtosis
CORRELATION AND REGRESSION ANALYSIS
Correlation coefficient (r )
Linear regression
Coefficient of determination
ELEMENTARY PROBABILITY
Definition of probability
Mutually exclusive events
Independent events
Combined events
2
,PERMUTATIONS AND COMBINATION
Factorial notation
Permutations
Combinations
I INTRODUCTION
Definitions of terms
Statistics is the study of how to collect, organize analyze and interpret numerical information
(data).
The main divisions of statistics are;
Descriptive statistics – refers to the statistical methods of describing and organizing data
e.g mean, median, mode, range, variance and standard deviation.
Inferential statistics – refers to the methods of using a sample to obtain information about
a population or making conclusions about a population from the sample statistics.
It is therefore, important to remember that the main role of inferential statistics is to draw
conclusions about a population based on information obtained from a sample.
Population – refers to all measurements of interest.
For example the weights of all pineapples in a field.
Sample – is simply a representative part of the population. For example, 100 weights
of pineapples.
DATA VARIABLES
Qualitative variables – no numerical value can be assigned, e.g, the colour of the hair.
3
, Quantitative variables – have numerical values, e.g. the number of people in a Sunday service.
Quantitative variables can be either discrete or continuous.
discrete variable – is one which naturally inherently contains gaps between successive
observation e.g. the number of family members in a family (it is either 2, 3, 4 etc but not 3.5
countries, number of chairs, number of animals, etc.
continuous variable has the property that between any 2 observable value lies another
observable value.
continuous variable takes values along a continuum, i.e along a whole interval of values, e.g.
length, weight, height, temperature, speed, PH of a solution etc.
An essential attribute of a continuous variable is that unlike a discrete variable, it can never
be measured exactly.
II COLLECTION OF DATA
It may be very difficult and tedious to collect data as the population may have a number of
characteristics and may be you are interested in only one or two characteristics e.g. pineapples in
a field, required to estimate the mean weight of the pineapples.
Data may be obtained through the following methods:
a) Survey
The most common method of collection of data is through surveys which have to be conducted
very carefully otherwise, the results would be of no value. Survey consists of two parts:
Planning
You need to consider:
Nature of problem.
Objective and scope of enquiry
Source of information
Type of enquiry to be conducted
Accuracy desired.
Executing the plan - involves various steps to put the plans in operation.
4
