WHAT IS STATISTICS?
Statistics is the mathematical science involved in the application of quantitative principles to the collection, analysis, and presentation of numerical data. The practice of statistics utilizes data from some population in order to describe it meaningfully, to draw conclusions from it, and make informed decisions. The population may be a community, an organization, a production line, a service counter, or a phenomenon such as the weather. Statisticians determine which quantitative model is correct for a given type of problem and they decide what kinds of data should be collected and examined. Applied statistics concerns the application of the general methodology to particular problems. This often calls for use of the techniques of computer-based data analysis. Some examples of statistical problems are: Interpretation of evidence linking environmental factors and disease, Design of experiments to evaluate effectiveness of pharmaceuticals, Mining data to discover target segments in the population, Market research to estimate demand for a new product,

Opinion polling in politics,
Estimation of the size of an animal population to aid in establishing regulations for conservation, Reliability studies for determining warranties,
Improving the quality of a service or manufactured item, Weather forecasting,
Analysis of errors in scientific experiments, and
Prediction of stock market prices.
Statisticians are key contributors to scientific methodologies. They use their quantitative knowledge to the design data collection schemes, process the data, analyze the data, and interpret the results. Further, statisticians often make critical evaluations on the reliability of data and whether inferences drawn from can be made confidently. They also help to identify misleading abuses of data that may be portraying an inaccurate account of a situation. Theoretical statistics concerns general classes of problems and the...

...compliments the regular mathematics and therefore both are tested in primary schools. Mathematics is the written application of operation. It teaches students to think clearly, reason well and strategize effectively. Mental Mathematics is the ability to utilise mathematical skills to solve problems mentally. The marks scored by pupils generate statistics which are used by teachers to analyse a student’s performance and development of theories to explain the differences in performance.
The Standard 3 class is where the transition from junior to senior level occurs where teachers expect the transference of concrete to abstract thinking would have occurred.
A common theory by many primary school teachers is ‘Students perform better in Mathematics than Mental math. Mental math is something that has to be developed and involves critical thinking. Mental math requires quick thinking and the student must solve the problem in their minds whereas in regular mathematics, the problem can be solved visually. Therefore, teachers should take these factors into consideration while testing and marking students in these areas.’
In this study, the statistics of 30 students of a standard 3 class of San Fernando Boys’ Government School will be analysed to determine the truth of this theory.
DATA COLLECTION METHODS
Mathematics and mental mathematics marks of term 1 of the class of 2013 were obtained from a Standard 3 teacher of San Fernando Boys’...

...Statistics in Business
Statistics is a mathematical science pertaining to the collection, analysis, interpretation or explanation, and presentation of data. It also provides tools for prediction and forecasting based on data. It is applicable to a wide variety of academic disciplines, from the natural and social sciences to the humanities, government and business ("Statanalysis Consulting", 2013). Statistics is used in decision making that affects our everyday lives.
The study of statistics is divided into two categories and has four levels of measurements. The two types of statistics are descriptive statistics and inferential statistics. Descriptive statistics is the organizing, presenting, and analyzing of data in an informative way. Inferential statistics is the methods used to estimate a property of a population on the basis of a sample. The four levels of measurements in statistics are nominal, ordinal, interval, and ratio. The first scale is nominal. The nominal level of measurement is the lowest level. Nominal data deals with names, categories, or labels. The next level is called the ordinal level of measurement. Data at this level can be ordered, but no differences between the data can be taken that are meaningful. The interval level of measurement deals with data that can be ordered, and in which differences between the...

...Department of Decision Sciences
Rational Decision Making
Only study guide for
DSC2602
University of South Africa
Pretoria
c 2010 University of South Africa
All rights reserved.
Printed and published by the
University of South Africa,
Muckleneuk, Pretoria.
DSC2602/1/2011
Cover: Eastern Transvaal, Lowveld (1928) J. H. Pierneef
J. H. Pierneef is one of South Africa’s best known artists.
Permission for the use of this work was kindly granted
by the Schweickerdt family.
The tree structure is a recurring theme in various branches
of the decision sciences.
Preface
Everyday life is full of decisions. What should I wear today? What should I eat? Should I buy
the red or blue shirt? Should I buy a speciﬁc house or buy a piece of land? What is the shortest
route from my house to work? . . . And many more.
Some of these decisions can be made without thinking or by guesswork. Some can be solved by
reasoning or emotions. Some are a bit more diﬃcult and may need additional information.
People have been using mathematical tools to aid decision making for decades. During World
War II many techniques were developed to assists the military in decision making. These developments were so successful that after World War II many companies used similar techniques in
managerial decision making and planning.
The decision making task of modern management is more demanding and more important
than ever. Many...

...Trajico, Maria Liticia D.
BSEd III-A2
REFLECTION
The first thing that puffs in my mind when I heard the word STATISTIC is that it was a very hard subject because it is another branch of mathematics that will make my head or brain bleed of thinking of how I will handle it. I have learned that statistic is a branch of mathematics concerned with the study of information that is expressed in numbers, for example information about the number of times something happens. As I examined on what the statement says, the phrase “number of times something happens” really caught my attention because my subconscious says “here we go again the non-stop solving, analyzing of problems” and I was right. This course of basic statistic has provided me with the analytical skills to crunch numerical data and to make inference from it. At first I thought that I will be alright all along with this subject but it seems that just some part of it maybe it is because I don’t pay much of my attention to it but I have learned many things. I have learned my lesson.
During our every session in this subject before having our midterm examination I really had hard and bad times in coping up with this subject. When we have our very first quiz I thought that I would fail it but it did not happen but after that, my next quizzes I have taken I failed. I was always feeling down when in every quiz I failed because even though I don’t...

...of 1000 flights and proportions of three routes in the sample. He divides them into different sub-groups such as satisfaction, refreshments and departure time and then selects proportionally to highlight specific subgroup within the population. The reasons why Mr Kwok used this sampling method are that the cost per observation in the survey may be reduced and it also enables to increase the accuracy at a given cost.
TABLE 1: Data Summaries of Three Routes
Route 1
Route 2
Route 3
Normal(88.532,5.07943)
Normal(97.1033,5.04488)
Normal(107.15,5.15367)
Summary Statistics
Mean
88.532
Std Dev
5.0794269
Std Err Mean
0.2271589
Upper 95% Mean
88.978306
Lower 95% Mean
88.085694
N
500
Sum
44266
Summary Statistics
Mean
97.103333
Std Dev
5.0448811
Std Err Mean
0.2912663
Upper 95% Mean
97.676525
Lower 95% Mean
96.530142
N
300
Sum
29131
Summary Statistics
Mean
107.15
Std Dev
5.1536687
Std Err Mean
0.3644194
Upper 95% Mean
107.86862
Lower 95% Mean
106.43138
N
200
Sum
21430
From the table above, the total number of passengers for route 1 is 44,266, route 2 is 29,131 and route 3 is 21,430 and the total numbers of passengers for 3 routes are 94,827.
Although route 1 has the highest number of passengers and flights but it has the lowest means of passengers among the 3 routes. From...

...Statistics is the study of the collection, organization, analysis, interpretation and presentation of data. It deals with all aspects of data including the planning of data collection in terms of the design of surveys and experiments.
Descriptive statistics is the discipline of quantitatively describing the main features of a collection of information, or the quantitative description itself. Descriptive statistics are distinguished from inferential statistics (or inductive statistics), in that descriptive statistics aim to summarize a sample, rather than use the data to learn about the population that the sample of data is thought to represent.
Statistical inference is the process of drawing conclusions from data that are subject to random variation, for example, observational errors or sampling variation. Initial requirements of such a system of procedures for inference and induction are that the system should produce reasonable answers when applied to well-defined situations and that it should be general enough to be applied across a range of situations. Inferential statistics are used to test hypotheses and make estimations using sample data.
Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many sciences
Qualitative Variables or Categorical Variable
Also known as categorical variables, qualitative variables...

...Worksheet 1 - Basic Concepts
1. What is Inferential statistics?
Inferential statistics uses observations of past occurrences or available data i.e. descriptive statistics to make decisions about future possibilities and/or the nature of the entire body of data. Inferential statistics draws conclusions or makes interpretations, predictions and inferences about a population based upon an analysis of a sample.
2. Give 2 different techniques which are used in descriptive statistics to represent the data.
Tables or graphs (histograms, boxplots, etc) or numerical summaries
3. Define each of the following terms:
a) Variable
The topics/issues under investigation in statistical analysis. The variable is a characteristic or property of the members of the population which may vary e.g. height, weight, perception etc.
b) Population
The total group about which information is being sought. If information is sought about voting intentions, the population is all those people eligible to vote in an electorate, or a state or the nation.
c) Sample
A sample is a group taken from the population. Most statistical situations do not allow an entire population to be used for analysis (usually because it is too large, the geographical dispersion of subjects, logistical issues, funding, time restraints etc) so a sample must be used. The sample chosen should be representative of and...