Using Data to Identify Biased Samples and Outliers

The sample that does not accurately represent the population.

• random sample

• biased sample

• sample

• population

A survey about public park usage interviews only people found in the parks on weekends. Is this sample biased or unbiased?

• Biased

• Unbiased

In a study to determine the most popular car color, data is collected by observing cars in a dealership's lot. This approach to sampling is:

• Biased

• Unbiased

Answer explanation

The correct answer is biased because the data is collected only from a dealership's lot, which may not represent the general population's car color preferences.

To determine the average number of books students read per year, a librarian only surveys students who are checking out books from the library. This sample is:

• Biased

• Unbiased

Answer explanation

The sample of students surveyed is biased because it only includes students who are already checking out books, not representing the entire student population.

A company surveys people at a mall on a weekday during working hours to know about job satisfaction. Is this sample likely to be biased or unbiased?

• Biased

• Unbiased

Answer explanation

The sample is biased because surveying people at a mall on a weekday during working hours may not represent the entire population's job satisfaction, as it excludes those who are not at the mall during those hours.

To understand the average time students spend on homework, a teacher asks all students in her class to report their homework time. This sample is:

• Biased

• Unbiased

Answer explanation

The sample is biased because it only includes students who voluntarily report their homework time, potentially excluding those who spend less time or do not want to share their data.

A survey is conducted by only interviewing people who have purchased a product from a specific brand. This type of sample is:

• Biased

• Unbiased

Answer explanation

The sample is biased because it only includes people who have purchased a product from a specific brand, leading to a skewed representation.

Choosing a sample by asking people who are exiting a cinema about their movie preferences is considered:

• Biased

• Unbiased

Answer explanation

Choosing a sample by asking people who are exiting a cinema about their movie preferences is considered biased because it only captures the opinions of those who watched a movie, excluding those who did not.

A researcher wants to know the average height of students in a school. He measures the heights of students in a basketball team and uses this data as his sample. Is this sample biased or unbiased?

• Biased

• Unbiased

Answer explanation

The sample is biased because it only includes students from the basketball team, which may not represent the entire school population.

a sample that does not accurately represent the population

• population

• sample

• random sample

• biased sample