Define the simple statistical concepts of average

Simple statistical concepts of average (mean) and standard deviation are used.  Estimating a relationship among variables needs a more advanced statistical technique. For instance, a firm may desire to estimate its cost function which means the relationship between cost concept and level of output. A firm can also wish to demand function of its product which is the relationship between demand for its product and factors which influence it. Estimates of costs and demand are generally based on data supplied by the firm. Statistical estimation technique used is known as regression analysis and is used to engender a mathematical model showing how a set of variables are related. This mathematical relationship can also be employed to produce forecasts.