Best Sampling Methods

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

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She picks the student in every 5th seat.

• Simple Random

• Systematic Random

• voluntary response

• convenience

Mrs. Croix is conducting a survey to find out the favorite snack of fifth and sixth graders. She will ask a sample of 100 students. Which of the groups below should be surveyed to get the BEST representative sample?

• 100 students at the movie theater

• the first 100 students who go to a local baseball game

• 5 students from each of the 20 local elementary schools

• 20 students from each of the 5 local fifth- and sixth-grade schools

each item or person in the population is as likely to be chosen as any other

• biased sample

• systematic random sample

• unbiased sample

• simple random sample

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

• Stratified 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.

• Cluster 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.

• 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

• 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.

Match the sampling methods to the proper scenarios.

• Simple Random Sample

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

• Stratified 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.

• Systematic Sample

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

• Clustered Sample

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

A group of lobbyists has a list of 100 senators. They decide to talk to every 7th senator on the list about their position on farm subsidies.

• Convenience

• Systematic

• Stratified

• Simple Random

A teacher puts all her students' names in hat, then selects 3 names from the hat. These students will take a standardized test.

• Convenience

• Systematic

• Stratified

• Simple Random

The president of a college randomly selects 2 students from each department to serve on a student advisory board.

• Convenience

• Systematic

• Stratified

• Simple Random

If you survey every third house on a street, what type of sampling technique are you using?