Definition Of Sample

A sample is a part of the population. When a survey is being carried out, a sample is taken from the population one wants to study.

Example of Sample

Conclusions are made about the quality of goods being manufactured in a factory, after inspectors carefully examine a sample of the goods to decide whether the quality is satisfactory.

Video Examples: Stratified Sampling (GCSE Mathematics Handling Data)

Solved Example on Sample

Ques: 3,000 children in a city with a population of 10,000 children watch television for at least 3 hours a day. 
How many children in a sample of 100 would watch television for at least 3 hours a day?

Choices:

A. 10 
B. 3 
C. 30 
D.20 
Correct Answer: C

Solution:

Step 1: Let x be the number of children in the sample who watch television for at least 3 hours a day. 
Step 2: 
Step 3:  [Write the proportion.] 
Step 4: x × 10000 = 3000 × 100 [Cross multiply.] 
Step 5:  [Divide both sides by 10000.] 
Step 6:  [Simplify.] 
Step 7: So, about 30 children in every 100 would watch television for at least 3 hours a day.

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