1. Statistics

2. What is Statistics?
The practice or science of collecting and analyzing numerical data in large quantities, especially for the purpose of inferring proportions in a whole from those in a representative sample.

3. Definitions

4. Survey A survey is a method of collecting information about people
Examples:
a) Survey about school
b) Survey about teachers
c) Survey about your favorite sport
d) numerous other examples

5. Data The facts or numbers gathered are called data
Data is either plural or singular depending on what you are using it for

6. Population
The population is the entire set of items from which data can be selected.
Example: I want to know what the favorite sport of students at Mueller Park is. What would the population be?

7. Census
A census is the data collected from every member of a population
Example: The US Census every 10 years

8. Sample
Most of the time it is impossible to get information from every member of a population.
When you only collect data from part of a population it is called a sample.
Samples should be representative of the entire population.

9. Parameter vs. Statistic
The characteristic used to describe the population is called a parameter.
The characteristic used to describe the sample is called a statistic.
Example: After the 2000 census, the United States Census Bureau reported that 7.4% of Georgia residents were between the ages of 10 and 14. Was a parameter or a statistic reported?

10. Example
A recent survey of 1000 teenagers from across the United States shows that 4 out of 5 carry a cell phone with them. a) What is the population of the survey b) Were the data collected in the survey a census? Why or Why not? c)Does the given statement represent a parameter or a statistic? Explain. d) Of those 1000 teenagers surveyed, how many carry a cell phone? How many do not carry a cell phone?

11. Discussion Questions

12. Describe the relationship between a population and a sample.

13. What do you think it means to say that a sample must be representative of the population?

14. What is the purpose of statistics?