Answer to Question 1
Probability sampling techniques include the following:
(1) Simple random sampling: assures each element in the population of an equal chance of being included in the sample.
(3) Systematic sampling: a starting point is selected by a random process and then every nth number on the list is selected.
(3) Stratified sampling: simple random subsamples that are more or less equal on some characteristic are drawn from within each stratum of the population.
(4) Cluster sampling: the primary sampling unit is not the individual element in the population but a large cluster of elements and clusters are selected randomly.
(5) Multistage area sampling: involves using a combination of two or more probability sampling techniques.
Answer to Question 2
a