Samples and Populations Statistics

As part of a 7th grade statistics project, the teacher brings a candy jar full of gumballs (red & green). The assignment is to estimate the proportion of red gumballs in the jar. Suppose one of the students draws 25 gumballs from the jar: 8 are red, 17 are green. What is the SAMPLE?

• 25 gumballs drawn

• all gumballs in the jar

• the students

• the 17 green gumballs

_______ is the entire group of objects or individuals considered for a survey.

• Sample

• Quartile

• Random Sample

• Population

_______ is a part of a group being surveyed.

• Sample

• Population

• Quartile

• Random Sample

True or False: all samples lead to a good prediction about an entire population.

• True

• False

What is the difference between a sample and a population?

A ​ (a)   is a set of all items or events which are of interest for some question or experiment.

It is generally the group you are trying to make predictions or learn something about.

For most studies, it is either impossible or impractical to obtain data on an entire population.

This is why you need to use a smaller selection of items.

A ​ (b)   is a selection of observations from a population.

We measure data in a known sample to make a prediction, or inference, about the population.

• population

• correlation

• sample

• causation

• ideation

• application

• understudy

• sample survey

• experiment

• observational study

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 you can not (or do not want) to count/survey everyone/thing in the population you use a SAMPLE.

Which best describes a sample?

• A sample is a complete count of every individual in the population.

• A sample is a subset of individuals chosen from a larger set.

Before a nationwide election, a polling place was trying to see who would win. Which choice best represents a sample?

• A selection of voters over age 50

• A selection of voters of different ages

• A selection of male voters

• All registered voters

part of a group

• sample

• population

• simple random sample

• survey

A ______ is a part of the entire group, used when it is too difficult to survey the entire group because of its large size.

(a)  

• sample

• survey

• population

• bias