Suppose a famous person reads every 10th letter of the 18 thousand letters coming in weekly. What type of sampling design is the person using in thiscase? Explain your answer.

What type of sampling isused?

A.

The person is using convenience sampling because the letter chosen is the easiest one to get.

B.

The person is using clustersampling, where each week is a cluster of letters.

C.

The person is using systematic sampling because the sample is chosen using a fixed periodic interval.

D.

The person is using simple random sampling because a random letter is chosen each week.

E.

The person is using stratifiedsampling, where the strata are the days of the week.