Month: February 2021

INTRODUCTION Network analysis looks at the way large projects such as construction projects, computerisation projects or managerial projects are planned and executed. The objective of network analysis is to set out a framework or plan such that the project is Read More …

FORECASTING Assumptions The reason for isolating the trend within a time series is to be able to make a prediction of its future values and thus estimate the movement of the time series. Before looking at the various methods available Read More …

INTRODUCTION Businesses and governments use statistical analysis of information collected at regular intervals over extensive periods of time to plan future policies. For example, sales values or unemployment levels recorded at yearly, quarterly or monthly intervals are examined in an Read More …

INTRODUCTION We’ve seen how the correlation coefficient measures the degree of relationship between two variates.With perfect correlation (r = +1.0 or r = -1.0), the points of the scatter diagram all lie exactly on a straightline. It is sometimes the Read More …

GENERAL When studying frequency distributions, we were always handling only one variable, e.g. height or weight. Having learned how to solve problems involving only one variable, we should now discover how to solve problems involving two variables at the same Read More …

RATIOS Introduction A ratio is another form of fraction just like a percentage, decimal or common fraction. It is a relationship between two numbers or two like values. Consider the following situation concerning a small town: To Reduce the Ratio Read More …

THE BASIC IDEA BUILDING UP AN INDEX NUMBER Introduction In commercial and economic affairs (and in some others, too) there are some very important quantities which are too complex to be measured directly; such things, for example, as the “level Read More …

INTRODUCTION In the previous study unit we discussed the idea of taking a sample of items from a much larger population. Calculations may be carried out on the sample data, and the results used to make inferences regarding the whole Read More …

INTRODUCTION   TO DISPERSION In order to get an idea of the general level of values in a frequency distribution, we have studied the various  measures  of  location   that  are  available.  However,   the  figures  which  go  to  make  up  a distribution Read More …

THE NEED FOR MEASURES OF LOCATION We looked at frequency distributions in detail in the previous study unit and you should, by means of a quick revision, make sure that you have understood them before proceeding. A frequency distribution may Read More …