The COVID-19 pandemic has infected over 38 million people around the world and is showing no signs of going away any time soon. Researchers worldwide are frantically working on developing an effective ...

In the case of studies where sample units are clusters, each unit is qualitatively classified into one of several groups according to some characteristic, and the ultimate units of observations are ...

Stratified random sampling is a method of sampling that divides a population into smaller groups that form the basis of test ...