Sample Techniques and Bias

To study the amount of time students spend doing homework each day, use a random number generator to select 25 freshmen, 25 sophomores, 25 juniors, and 25 seniors to survey.

• Convenience Sample

• Simple Random Sample

• Stratified Random Sample

• Interval Sample

The school librarian wants to determine how many students use the library on a regular basis.  What type of sampling method would she use if she chose to use a random number generator to randomly select 50 students from the school's attendance roster.

• Convenience Sample

• Simple Random Sample

• Stratified Random Sample

• Interval Sample

Mrs. Trahan samples her class by selecting 5 girls and 7 boys.  This type of sampling is called?

• Stratified

• Systematic

• Simple

• Cluster

Mrs. Trahan samples her class by picking 10 numbers from her hat and each number is assigned to a student. This is ______________ random sampling.

• Systematic

• Simple

• Stratified

• Cluster

Tanya wants to know the percent of people likely to attend the upcoming musical at school. She asks each person in the musical how many people they know who are coming to make a prediction. Why is this sample biased?

• Drama students are more likely to lie.

• Musicals are better attended than plays.

• The drama teacher was not asked.

• The sample is not random and not representative of the entire school population.

Answer explanation

The sample is not random and not representative of the entire school population, as it only includes people involved in the musical, leading to bias.

In order to estimate the proportion of students that text while driving, a school administrator selects a simple random sample of students from a list of all students at the school who have parking permits. The students are called to the office, one at a time. The administrator asks each student, “Do you text while driving, even though you are not supposed to?” Based on the survey, the administrator estimates that only 2% of students with parking passes text while driving. What potential bias is present in the design of this survey and what is the likely direction of the bias?

• The sample proportion is likely an underestimate of the population proportion due to response bias.

• The sample proportion is likely an underestimate of the population proportion due to undercoverage.

• The sample proportion is likely an underestimate of the population proportion due to nonresponse.

• The sample proportion is likely an overestimate of the population proportion due to response bias.

• The sample proportion is likely an overestimate of the population proportion due to undercoverage.

A student wants to know which type of pizza the students at his high school prefer. Which option would give a 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.

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

• Asking all the students in the hot lunch line.

• Asking 10 students from each homeroom

• Asking 100 random students, chosen by drawing names from a hat

• Asking all the 10th graders

A radio station is discussing a controversial policy enacted by the local police department. They poll listeners by having them call in to the radio station. Which of the following is the most significant source of bias?

• Leading questions on the survey

• Voluntary Response Bias

• Survivorship Bias

• Self-reported response bias

A tax preparation company wants to see how satisfied its customers are with their services. Which of the following would give them the best unbiased sample?

• looking at customer reviews on their social media page

• questioning the first 25 people that call the company

• asking the last 25 people on an alphabetical list of all of their current customers

• surveying a random sample of customers from a list of all of their current and previous customers