IB Sampling Methods

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

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.

Match each example with the sampling method to survey 100 employees of a company that has 1000 employees.

• Simple Random Sampling

• The company has 800 female employees and 200 male employees. You want to ensure that the sample reflects the gender balance of the company, so you sort the population into two strata based on gender. Then you use random sampling on each group, selecting 80 women and 20 men, which gives you a sample representative of 100 people.

• Systematic Sampling

• You want to select a simple random sample of 1000 employees of a social media marketing company. You assign a number to every employee in the company database from 1 to 1000, and use a random number generator to select 100 numbers.

• Stratified Sampling

• All employees of the company are listed in alphabetical order. From the first 10 numbers, you randomly select a starting point: number 6. From number 6 onwards, every 10th person on the list is selected (6, 16, 26, 36, and so on), and you end up with a sample of 100 people.

• Cluster Sampling

• The company has offices in 10 cities across the country (all with roughly the same number of employees in similar roles). Travel to every office to collect your data is unreasonable, so use random sampling to select 3 offices.

Match the sampling methods to the proper scenarios.

• Simple Random Sample

• From number 5 onwards, every 10th person on an alphabetical list of employees is selected

• Stratified Sample

• You sort the population into two strata based on gender, then you use random sampling on each group

• Systematic Sample

• You assign a number to every employee in the company database from 1 to 100, and use a random number generator to select 10 numbers.

• Clustered Sample

• The company has offices in 12 cities across the country. You use random sampling to select 3 offices

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected. 

• systematic

• simple random sample

• convenience

• volunteer response

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.
This is a form of:

• Simple Random Sample

• Stratified Random Sample

• Voluntary Response

• Systematic Random Sampling

An independent research company wants to go door to door to survey people in the city of Fontana. The company decides to number all blocks within the city limit, randomly choose 50 blocks and survey all households on each selected block. 
This is an example of:

• Simple Random Sample

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sampling

Farmer Joe's apple tree farm is set up in 100 rows.  He counts the number of apples produced on every 10th row to estimate the number apples produced on the whole farm.  This is _____________ sampling.  

• Random

• Stratified

• Voluntary-Response

• Systematic