The school office orders boxes of penciled and boxes of pens in a ration of 5 to 2 if 60 boxes of penciled are ordered how many boxes of pens should be ordered

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected