Answer:
For this case, the method used would be simple random sampling since random digit dialing assumes that all possible people in the population have the same probability of being chosen.
We may have a non-response bias, because if a selected person does not choose the phone, we have no answers to the questions and there is no data available.
We may also have under coverage bias because some people may not have a phone and in this case these people would be excluded from the study
Step-by-step explanation:
For this case is important to remember the different types of sampling methods
Simple random sampling is a method where we select a sample size n and each individual in the population are equally likely to be selected.
Stratified random sampling is a method on which we select samples from subgroups of the population usually called strata.
Convinience sampling is a method that use a random number so select the sample
Cluster sampling is a method that separates the population in natural subgroups with no intersection between them and some of the groups are selected for the sample.
For this case, the method used would be simple random sampling since random digit dialing assumes that all possible people in the population have the same probability of being chosen.
Sources of bias
We may have a non-response bias, because if a selected person does not choose the phone, we have no answers to the questions and there is no data available.
We may also have under coverage bias because some people may not have a phone and in this case these people would be excluded from the study
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