Economizing of resources means that the resources are used in the best possible manner so that maximum output is achieved per unit of input. In other words, it refers to optimum and efficieint  utilization of the scarce resources.

An economic problem is basically the problem of choice which arises because of scarcity of resources. Human wants are unlimited but means to satisfy them are limited. Therefore, all human wants cannot be satisfied with limited means. Wants differ in intensity and limited resources have alternative uses. In such a background, every consumer tries to satisfy his maximum wants. Therefore, one has to choose as to what goods one should consume and in what quantity. Economic problem arises the movment problem of choice arises. Actually speaking, economic problem is basically the problem of choice.

A number of economics problems can easily be understood by the use of statistics. It helps in formulation of economic policies e.g., basic economic activities like production, consumption etc. use statistics. The importance of statistics in various parts of economics as follows:

1. Statistics in consumption: To obtain the knowledge of how different groups of people spend their income on consumption. The data of consumption are useful and helpful in planning their budget and in improving their standards of living.
2. Statistics in production: The comparative study of the production process is done with the help of statistics. The statistics in production is very useful and helpful in the adjustment of demand and supply and for determining the quantity of production of the commodity.
3. Statistic in distribution: Statistical methods are used in solving the problem of distribution of national income among various factor of production i.e, land, labour, capital and entrepreneur.

Importance of statistics:

1. Formulation of economic laws: it helps in formulation of laws and models e.g. law of demand  has been developed by the inductive method of genralisation which is based on statistical principles.
2. Understanding economic problems: it plays a  vital role in understanding and solving economic problems such as poverty, unemployment, etc.
3. Study of market structures: study of monopoly, monopolistic competition, oligopoly, and monopolistic competition requires statistical comparison of market prices, cost, and profits of individual firms.
4. Intersectoral anf intertemporal  comparison:  statistics helps in the comparision of different sectors of the economy and also helps in comparison of variables in two different time periods
5. Economic forcasting: by using statistical tools , methods, and techniques one can forcast e.g growth of the country in the coming  fiscal year or rate of inflation in the coming month. 

Differences between cardinal utility and ordinal utility are

1. The subject matter of economics includes microeconomic and macroeconomics.
2. Microeconomics, studies the behaviour of individual economic units of an economy, like households, firms, individual consumers and producers etc. It does not study the economy as a whole.
3. Macroeconomics is the part of economic theory that studies the economy as a whole, such as national income, aggregate employment, general price level, aggregate consumption, aggregate investment, etc.