The best graphic representation of frequency distribution of data gathered of a continuous variable is:
Histogram Statistical data are of two types: Qualitative Quantitative Qualitative data -is one in which the size or magnitude of the characteristic or attribute cannot be measured. - there is only one variable i.e. the number of persons and not the characteristic or attribute - persons with the same charactersitic are counted to form specific groups or classes. - eg: male/female, black/white, urban/suburban/rural, vaccinated/not vaccinated, treated/not treated. - as seen in the example the attribute or characteristic, vaccinated/not vaccinated cannot be measured. Only the frequency of persons vaccinated or not vaccinated varies. - Qualitative data are discrete in nature such as number of deaths in different years, population of different towns, persons with different blood groups in a population, and so on. Qualitative data are represented in Nominal or Ordinal scale. Quantitative data -is one in which the characteristic or attribute is variable. It has a magnitude that can be measured. - eg. : height, weight, temperature, blood pressure, pulse rate - here there are two variables, both the characteristic i.e. height or weight and frequency of persons. - The quantitative data obtained from characteristic variable are also called continuous data as each individual has one measurement from a continuous spectrum or range such as body temperature from 35 C to 42 C, height 140 cm to 190 cm, pulse rate from 70 bpm to 90 bpm. - quantitative data are represented on Interval or Ratio scales. The statistical details are presented, for easy viewing and understanding, in the form of tables, graphs and diagrams.
Simple bar graph
Multiple bar
Line diagram
Histogram