Mid-Chapter Quiz
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A population consists of all the members of a group of interest. A sample is a subset of the population.
Sample: 100 random children and parents
Population: All children and parents
Classification: See solution
Explanation: See solution
A population consists of all the members of a group of interest. Since it may be impractical to examine every member of a population, a sample — a subset of the population — is sometimes selected to represent the population. The sample can then be analyzed to draw conclusions about the entire population.
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A cereal company invites 100 random children and parents to test a new cereal and records their reactions. |
Here, the population consists of all the children and parents. The sample consists of randomly selected 100 children and parents. Samples can be classified into different categories.
| Name | Characteristic |
|---|---|
| Simple Random Sample | Each member of the population has an equal chance of being selected. |
| Systematic Sample | Members are selected according to a specified interval from a random starting point. |
| Self-selected Sample | Members volunteer to be included in the sample. |
| Convenience Sample | Members that are readily available or easy to reach are selected. |
| Stratified Sample | The population is first divided into similar, nonoverlapping groups. Members are then randomly selected from each group. |
In our situation, we are told that the company invites 100 random children and parents. Since we are not told any more details, we can assume that the cereal company gathered the sample without any unnecessary effort — therefore the sample was selected randomly from people easy to reach. Therefore, this is a convenience sample. Let's finally summarize our answers in a table.
| Sample | 100 random children and parents |
|---|---|
| Population | All children and parents |
| Classification | Convenience sample |
| Explanation | It is easier to gather a sample from people that are easy to reach. |