Question

to conduct a survey about the type of phone service most people in greenville prefer, 10 different blocks in the neighborhood are chosen. on these 10 blocks, 10 houses are selected at random, and then each resident of each of those houses is interviewed. this type of sampling method is
simple random sampling.
stratified sampling.

cluster sampling.

Explanation:

1. Simple Random Sampling: Involves randomly selecting individuals from the entire population. Here, we first select blocks (clusters) then houses, so not simple random.
2. Stratified Sampling: Divides the population into strata (groups with similar characteristics) and samples from each stratum. The problem doesn't mention dividing into strata with similar traits, so not stratified.
3. Systematic Random Sampling: Selects every k-th individual after a random start. The method here doesn't follow this pattern.
4. Cluster Sampling: Divides the population into clusters (here, blocks), randomly selects some clusters, and then samples all or part of the selected clusters. Here, 10 blocks (clusters) are chosen, then 10 houses (and their residents) from each block are surveyed, which fits cluster sampling.

Answer:

D. cluster sampling.