Identify the type of sampling used: random, systematic, convenience, stratified, or cluster. To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at MicrosoftMicrosoft selects every 1414th software CDsoftware CD that comes off the assembly line starting with the eightheighth until she obtains a sample of 140140 software CDssoftware CDs. Which type of sampling is used?
Systematic sampling is used.
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Every 14th CD.
So systematic sampling is used.