The ground of frequencies - one of data processing methods applied in mathematical statistics which collects by the analysis and data processing in the scientific and practical purposes.
Instruction
1. Statistical data are result of inspection of a certain quantity of the phenomena, objects, their signs and are mass. For their processing abstract mathematical models are used.
2. Mathematical statistics is divided into descriptive and analytical which is called still the theory of statistical conclusions. Descriptive statistics includes methods of the description of data, drawing up tables, etc. Analytical processes these data, formulates conclusions. It is also interconnected with probability theory.
3. The ground of frequencies is a schedule of density of probability of a random variable. It represents distribution of discrete and continuous signs. The schedule of the ground of frequencies is the broken line connecting the points corresponding to average values of intervals of group (axis X) and frequencies of intervals (axis U).
4. To build the ground of frequencies, systematize primary data of experience (observation or process), group them in the necessary sign, define intervals which contain some range of values of sign. Usually they get out equal that facilitates data processing. The number and size of intervals is defined in each case separately and considers the purposes of experience (observation), the volume of sample of data, variation of sign of an object.
5. Make the table on the basis of the systematized data. Construct the system of coordinates on graph paper. Designate on a horizontal axis, an abscissa, values of the varying sign, and on a vertical axis, ordinate - the frequency of its change. Take data from the made table.
6. Find points of crossings of these values. Connect consistently them among themselves. The broken line is the ground of frequencies of your experience (observation) and reflects change of sign of an object in the set interval.
7. This way of data processing of mathematical statistics is widely applied in sociology, biology, medicine and also to the analysis and a research of many fields of science.