Give two examples each of sample, population and variable.
Sample is the subset of the population. In other words, a small set selected from the population for statistical study is referred as sample population. For example, in order to study the growth pattern of students, the heights of 50 students (sample) are recorded from a school of 500 students (population). Similarly, in order to record the level of sugar in the blood, blood sample of 2000 people (sample) was taken from 20,000 people (population).
Population refers to the aggregate or the total items to be studied for an investigation. In the above examples, 500 students and 20,000 people constitute the population.
Variables are the characteristics of a sample or population that can be expressed in numbers such as, height, income, age, etc.