Question

The World Health Organization wishes to estimate the mean density of people per square kilometer, they collect data on 56 countries. Justify for full credit. (a) Which of the followings is the variable? (i) All countries in the world (ii) Density of people per square kilometer (iii) Set of densities of people per square kilometer of all countries (iv) Set of densities of people per square kilometer of 56 countries. The World Health Organization wishes to estimate the mean density of people per square kilometer, they collect data on 56 countries. Justify for full credit. (a) Which of the followings is the variable? (i) All countries in the world (ii) Density of people per square kilometer (iii) Set of densities of people per square kilometer of all countries (iv) Set of densities of people per square kilometer of 56 countries

Answer 1

A variable is a parameter which vary according to the factors like time, place etc .

Here we are estimating mean density of people per square kilometre.

The density of people per square kilometre is the variable in the given problem.

All countries in the world is a population.

set of densities of people per square kilometre is a population parameter

set of densities of people per square kilometre of 56 countries is a sample statistic.

Option (ii) is the variable.