Question

identify the type of sampling
we divide the town into many different zones, then randomly choose 5 zones and survey everyone in those zones
a student conducts a facebook poll asking students their opinions about mandating vaccines for the fall
an organization is looking to assess the performance of smartphones across kenya. the researchers divide the countrys entire population up into cities and further select towns with the highest population and filter by those using mobile devices
a drug manufacturer is researching adverse side effects on a countrys population. the researcher takes a sample of people from each demographic of the country

Explanation:

1. First Scenario: Dividing the town into zones (clusters) and randomly selecting some clusters to survey all within them is Cluster Sampling.
2. Second Scenario: A Facebook poll relies on volunteers (students who choose to respond), so it's Voluntary Response Sampling.
3. Third Scenario: First dividing into cities (clusters), then selecting specific towns (with highest population) and filtering (using mobile devices) – this is a form of Stratified Sampling (or a mix, but key is dividing into groups and selecting from specific groups) or more precisely, maybe a form of Purposive Sampling, but more likely, if we consider the initial division into cities (clusters) and then selecting based on population (a criterion), but another angle: if we first divide into cities (strata) and then select towns (maybe clusters) with highest population, but the filtering by mobile devices is a secondary step. However, the main initial division into cities and then selecting specific ones (with highest population) could be considered a form of Stratified Sampling (if cities are strata) or Cluster Sampling (if cities are clusters). But more accurately, when we divide into groups (cities) and then select specific groups (towns in cities with highest population) and then filter, it's a type of Sampling with multiple stages, but the closest basic type here might be Cluster Sampling (if cities are clusters) or Purposive. But maybe the intended is Cluster Sampling (divide into clusters, select some clusters, but here they select based on population, not random). Wait, no – the first part: "divide the country's entire population up into cities" (clusters), then "select towns with the highest population" (not random, so maybe Purposive Cluster Sampling, but in basic sampling, if we divide into clusters and select some (even with a criterion), but the key is that they survey within those selected clusters? Wait, no, the problem says "assess the performance of smartphones... filter by those using mobile devices" – maybe the intended is Convenience Sampling (selecting towns with highest population is a convenience/criterion), but also, if we first divide into cities (clusters) and then select towns (clusters) with highest population, it's a form of Cluster Sampling with a non - random selection of clusters (purposive cluster sampling). But maybe the answer expected is Cluster Sampling (since they divide into clusters and select some, even with a criterion).
4. Fourth Scenario: Taking a sample from each demographic (strata) of the country is Stratified Sampling (dividing the population into strata (demographics) and sampling from each stratum).

Answer:

1. Cluster Sampling
2. Voluntary Response Sampling
3. Cluster Sampling (or Purposive Sampling, but more likely Cluster Sampling as per basic types)
4. Stratified Sampling