a band director is trying to decide what musi...
a band director is trying to decide what music to play for the halftime show. she surveys the marching band students to get their opinions about which music they would prefer. which of the following sampling techniques would provide a stratified random sample that would accurately represent the students’ opinions? have a computer randomly sort the band members, then select the first 30. randomly select 2 students from each type of instrument (trumpet, saxophone, clarinet, etc.). randomly pick a letter of the alphabet and survey every student whose last name begins with that letter. randomly pick a year of students (freshman, sophomore, junior, or senior) and survey every student from the selected group.
Answer
# Answer:
B. Randomly select 2 students from each type of instrument (trumpet, saxophone, clarinet, etc.)
# Explanation:
## Step1: Define stratified random sampling
Stratified random sampling divides population into subgroups (strata) and samples from each.
## Step2: Analyze each option
- Option A: Random - sort and pick first 30 is simple random sampling.
- Option B: Dividing by instrument type (strata) and sampling from each is stratified random sampling.
- Option C: Sampling by last - name letter is not stratified by relevant subgroups.
- Option D: Sampling one grade level is not stratified sampling as it doesn't sample from all strata (all grade levels).