Identifying Sample Types: Representative, Random, and Biased

The video tutorial explains how to identify representative, random, and biased samples. It provides examples of biased samples, such as a mayor surveying only her neighborhood, and random samples, like using a number generator at an airport. The tutorial emphasizes the importance of random sampling for accurate representation and discusses various contexts, including schools, families, and technology, where sampling is applied. It also highlights the pitfalls of non-representative sampling and the benefits of using random sampling techniques.

Why is the mayor's survey of her own neighborhood considered biased?

• She surveyed too many people.

• She used a random number generator.

• She included people from other towns.

• She only surveyed people who live close to her.

Why is Mason's survey of all the children in the neighborhood not biased?

• He only asked his friends.

• He included every child in the neighborhood.

• He asked only the children who were at the park.

• He used a biased sampling method.

What makes Madison's sample of five students from each class representative?

• She chose students from only one class.

• She chose students who volunteered.

• She chose students randomly from every class.

• She chose students based on their grades.

Why is Madison's method of picking marbles considered random?

• She picked the marbles with her eyes closed.

• She looked at the marbles before picking.

• She picked the marbles based on their color.

• She picked the marbles from the top of the bag.

How does the number generator at the airport ensure a random sample?

• It selects people who arrive early.

• It selects people based on their appearance.

• It selects people who have traveled frequently.

• It uses a random number generator to select individuals.

Why is Dahlia's survey of only first graders not a random sample of the school?

• She included students from all grades.

• She only surveyed first graders.

• She surveyed teachers as well.

• She used a random number generator.

Why is the biologists' study of 37 out of 47 ponds considered not biased?

• They studied all the ponds.

• They only studied the ponds closest to the lake.

• They randomly selected a large number of ponds.

• They chose the ponds based on their size.

What makes Elizabeth's family survey representative?

• She used a random number generator.

• She interviewed every member of her family.

• She only interviewed the children.

• She only interviewed the adults.

Why is the government's survey of only millionaires considered biased?

• They included people from all income levels.

• They used a random number generator.

• They only asked millionaires.

• They surveyed people from different countries.

How does rolling a dice to assign tests ensure a random sample?

• It assigns tests based on participants' preferences.

• It assigns tests based on participants' scores.

• It assigns tests randomly based on the dice roll.

• It assigns tests based on participants' age.