BRANCHES OF STATISTICS AND MODERN USE OF STATISTICS
Statistics has been defined in two ways: namely:
- As numerical facts systematically collected, and
- As a scientific method of making inference on the basis of such collected information
Descriptive statistics is the aspect of statistics that studies a body of statistical data and no generalization is made from the results obtained. This area of statistics covers such statistical techniques as collection of data, classification of data, drawing of histogram, polygon, charts and other types of statistical graphs, computation of sample characteristics such as the mean, mode, median, variance, standard deviation, sample coefficient of regression and correlation, index method and other descriptive techniques. On the other hand, inferential statistics is the branch of statistics that studies a group of data in order to use the results obtained in making generalization on a larger group of data. In other words, statistical inference is the use of sample results to reach conclusion about populations from which the samples have been drawn.
MODERN USES OF STATISTICS
We have already seen the important role played by statistics at its early stages of development. In modern times statistics has found application ‘i various fields of human endeavour. The science of statistics is an indispensable weapon in economic planning. Using statistics, economic planners provide the government with information regarding the country’s population, population density, birth and death rates, manpower resources, labour productivity, level of industrial and agricultural production, distribution of national income, the country’s requirements with regard to capital investments including building of schools, hospitals, factories, roads and so on. No doubt, such information helps the government in policy-making.
Statistics is widely used in business and industry. The complexities of modern industrial production and business management make it compulsory that managem.ent be furnished with statistical data such as those concerning output, cost of raw materials, labour, sales, etc., in order to ensure greater effectiveness in the combination of factors of production. The modern manager operates in the midst of uncertainties and competition. Very often he needs to make crucial business decisions affecting production and sales, stock control, prices, personnel management, etc. Such decisions are not made by mere guess work; rather, they are based on sound scientific analysis of facts using various statistical methods.
One of the most important statistical techniques that has found wide application in modern industrial concerns is statistical quality control. Statistical quality control provides industrial management with tools for controlling the quality of manufactured products. The role of statistics here includes the keeping of systematic records of quality, the development of measures of variation in product quality, and the application of the theory of random sampling for the establishment of quality control limits.
Statistics is also widely used in agriculture for the analysis of agricultural experiments. Sir Ronald Fisher – a prominent statistician was the first to apply statistical methods in agriculture, and in the early 1920’s developed one of the most important statistical techniques known as of variance. Statistics is of importance in medicine and medical h. Medical records of patients provide information on the causes and of various diseases, Statistical tests are carried out on new drugs to their effectiveness. In fact, the modern doctor needs a good knowledge of statistics for greater efficiency in his profession.
Many other sciences – meteorology, geology, education, to mention few make use of statistical methodology in reaching decisions baa- incomplete information. There is no doubt then, that statistics affects all aspects of our life.