Representative vs Non Representative Sample

If you survey students in your town then your population is limited to students in your town.

What makes a sample representative?

• The sample is representative if it includes people from all over the world

• The sample is representative if it includes people from the same town

• The sample is representative if it includes people from the same country

• The sample is representative if it accurately reflects the group it is supposed to represent

The sample represents the population.

Choose the answer that says "Representative Sample"

• Random Sample

• Biased Sample

• Representative Sample

Look at our population, 20% of the dots are red.

A representative sample would ALSO have 20% red dots.

Draw what a representative sample would look like.

There are 15 circles in the population.

20% of the circles are red.

The best representative sample would also have 20% red circles.

It is RARE for your sample to be EXACTLY the same. We hope the sample is SIMILAR or CLOSE.

In a sample of 3 each circle is 33% (so not 20%). Which sample is the MOST representative of the population?

Which is the BEST sample of the 4 random samples?

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Answer explanation

The population is MOSTLY purple and SOME red.

This is the only sample that is MOSTLY purple and some red.

This is the MOST representative sample even though it is not exactly the same as the population.

The sample represents the population.

Choose the answer that says "Representative Sample"

• Random Sample

• Biased Sample

• Representative Sample

A sample should be

• representative of  only middle school students only

• a very large group

• representative of the population

• representative of people who volunteer

If the population is ALL 7th Graders Then you want to take a sample from ALL 7th graders. A sample is part of the population but not all of it. Select the one below that is true

• A sample is a smaller group selected from the population

• A sample is the entire population

• A sample is a larger group than the population

• A representative sample is not related to the population

When taking a sample You want to choose individuals/objects FROM THE POPULATION Anyone in the population could potentially be part of the sample is ideal. Which below is the best way to take a sample?

• Only select individuals who are easily accessible

• Select individuals based on personal bias

• Select individuals randomly from the entire population

• Only select individuals who respond to a public survey

All students' names have been placed in a bowl. To determine what the favorite subject is of JDMS students, Mrs. Brantley draws out 100 names and asks those students what their favorite subject is. Is this representative or biased?

• Representative Sample

• Biased Sample

Middle school students are chosen at random to determine the average shoe size of middle school students.

• Representative Sample

• Biased Sample