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.