Answer:
- Pulling 50 names from a hat. <-> e. Simple Random
- Asking your 20 closest friends <-> b. Convenience
- Separating all students by grade level, and selecting 10 students from each grade <-> c. Stratified
- Call every 15th phone number on every 5th page of the phone book <-> d. Systematic
- Dividing by population by voting precinct, and sampling everyone in the precints selected <-> a. Cluster
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
- Pulling 50 names from a hat
All options in the hat and pick some of them. So Simpel Rando.
- Pulling 50 names from a hat. <-> e. Simple Random
- Asking your 20 closest friends
Closest friends lead to convenience. so
- Asking your 20 closest friends <-> b. Convenience
- Separating all students by grade level, and selecting 10 students from each grade
Divided the population into groups, and choose some from each group. Stratified.
- Separating all students by grade level, and selecting 10 students from each grade <-> c. Stratified
- Call every 15th phone number on every 5th page of the phone book
Every kth person. Systematic.
- Call every 15th phone number on every 5th page of the phone book <-> d. Systematic
- Dividing by population by voting precinct, and sampling everyone in the precints selected
Division into groups, and choosing everyone from each group. Cluster
- Dividing by population by voting precinct, and sampling everyone in the precints selected <-> a. Cluster
