Random Sampling Methods

For a school project, three students need to produce a sample of students at their school. Which of the following methods leads to a random sample?

• Numbering all the students and produce the sample from a random list of numbers

• Calling for volunteers at the school assembly

• Calling for volunteers via social media

• Asking each of their friends to name three further friend2

At a local golf club, there are 50 male members and 30 female members. A representative sample of 10 random male members and 6 random female members is chosen. Which of the following is the sampling method used?

• simple random sampling

• systematic random sampling

• stratified sampling

To find out what sort of events they should plan, the student government officers at OVHS send a survey to 40 students, 10 in each grade, whose names were randomly selected. The population they are interested in is...

• only the 30 OVHS students

• all students at OVHS

• only students who respond to the survey

• all high school students in HB

is when every person in the target population has an equal chance of being sampled.  Typically, researchers will have the names of every person in the target population, and will select names at random.  This method is often used in telephone surveys before an election - every telephone number has an equal chance of being selected.

• random sampling

• convenience sampling

• volunteer sampling

• snowball sampling

Which sampling method ensures that every member of the population has an equal chance of being selected?

• Random sampling

• Stratified sampling

• Convenience sampling

• Systematic sampling

Which sample best represents a random sample of 240 homes in a neighborhood?

• Assign each home a number from 1 to 240. The use of a random generator to generate 12 numbers from 1-240.

• Drive through the neighborhood, and choose every twentieth home you come to.

• Choose 6 homes with odd-number street

• Park at the entrance of the neighborhoo, and stop the first 12 cars to ask which home is theirs.

To randomly select 25 basketball players from the 300 players in the NBA, I would:

• Number the players from 01-25, read 3 digits at a time from a random table, discarding repeats and numbers over 25, and then stop when I reach 25.

• Number the players from 0-299, read 2 digits at a time from a random table, discarding repeats and numbers over 299, and stop when I reach 25.

• Number the players from 01-299, read 2 digits at a time from a random table, discarding repeats and numbers over 300, and stop when I reach 25.

• Number the players from 001-300, read 3 digits at a time from a random table, discarding repeats, 000 and numbers over 300, and stop when I reach 25.

A student wants to know which type of pizza the students at his high school prefer. Which option would give an unbiased, representative sample:

• Asking all the students in the hot lunch line.

• Asking 10 random students from each homeroom.

• Asking every other student who gets off a school bus.

• Asking all the 10th graders.

Students at North River High School are assigned to home rooms with 25 students each. You randomly select 4 homerooms and gather data from each of the 100 students in these classes.

What type of sampling method was used?

• Simple Random

• Cluster

• Stratefied

• Systematic

Which of the following doesn’t result in some form of bias?

• Choosing AP students to survey regarding their GPA in order to estimate the average GPA in a school.

• Polling a group of potential voters outside a Republican campaign office in order to estimate the proportion of city residents who favor a particular candidate.

• Surveying people who work in the marketing department of a large corporation in order to assess employee satisfaction with management policies.

• Choosing a stratified random sample of juniors and seniors at a high school in order to estimate the proportion of juniors and seniors who plan to go on to college.

• Asking shoppers leaving a grocery store if they think groceries should cost less in order to estimate the proportion of city residents who think groceries cost too much.