Sampling Methods and Bias in Surveys

The video tutorial covers lesson 14 on fair sampling methods. It begins with an introduction to sampling and discusses a survey conducted at a movie theater to estimate the average age of moviegoers. The tutorial then explores different sampling methods for a school election and evaluates methods to survey caffeine consumption. An experiment involving straw lengths is conducted to demonstrate sampling techniques. Finally, the video explains random sampling techniques and the use of random number tables.

What age range was most represented in the movie theater survey?

• 16 to 19

• 12 to 15

• 8 to 11

• 4 to 7

Why might asking only Lynn's basketball team about their voting preference be biased?

• They are likely to vote for her.

• They are not interested in the election.

• They are all in the same grade.

• They represent the entire school.

Which sampling method would likely provide a more representative sample of the student body?

• Polling only the students in the library

• Asking three students from each homeroom

• Surveying the first 15 students who arrive at school

• Asking every third girl in the lunch line

What is a potential issue with surveying people at a coffee shop about caffeine consumption?

• They might not drink caffeine.

• They are likely to consume more caffeine.

• They are not interested in surveys.

• They represent all caffeine consumers.

Which location might provide a less biased sample for the caffeine study?

• A morning yoga class

• A park in the evening

• A grocery store

• A coffee shop

In the straw drawing activity, why might the initial sample not be representative?

• The straws are not numbered.

• The shorter straws are more colorful.

• The longer straws are more likely to be picked first.

• The straws are all the same length.

How could increasing the sample size in the straw activity improve accuracy?

• By reducing the number of straws

• By making the straws more visible

• By increasing the likelihood of selecting shorter straws

• By ensuring all straws are the same length

What is a fair method to select a sample of straws?

• Picking the first five straws you touch

• Selecting straws from the top of the pile

• Choosing straws based on color

• Using a spinner with numbered sections

Why can't computers produce truly random numbers?

• They follow predictable instructions.

• They are too slow.

• They lack the ability to generate numbers.

• They rely on user input.

What method did statisticians use before computers for random sampling?

• Random number tables

• Drawing lots

• Dice rolling

• Coin flipping