1. Types of Variables
*Do Survey

2. Warm-up: Survey
Complete the survey…..we will use this data later!

3. Individuals
The individuals are the objects described by a set of data.
*Individuals may be people, animals, or things.
*It’s the who or what that we are studying.

4. Variable It is any characteristic of an individual.
It can take different values for different individuals.
Example: High school’s student data base.

5. New Data Set…Questions to ask yourself.
Who are the individuals described by the data?
How many individuals are there?
What are the variables?
In what units is each variable?

6. Types of Variables Categorical – also known as qualitative
Data from individual is placed into a category
Quantitative – also know as numerical
Takes numerical values and it makes sense to find an average

7. Quantitative or Qualitative?
Voter’s region – (North, South, etc)
Age – (in years)
Quan
Systolic Blood pressure (mm of mercury)
Quan
Level of calcium in the blood (micrograms/ml)
Quan
Smoker – (yes or no)
Qual

8.
Hundreds of thousands of students from Australia, Canada, New Zealand, South Africa, and the United Kingdom.
Let’s pick 10 students…

9. Who are the Individuals in this data set?

10. What variables were measured
What variables were measured? Identify each as categorical or quantitative. In what units were the quantitative variables measured?

11. Describe the individual in the highlighted row.

12. Distribution
The distribution of a variable tells us what values the variable takes and how often it takes these values.
It represents the pattern of variation of a variable.

13. Who are the individuals? What variables did he measure?
Jake is a car buff who wants to find out more about the vehicles that students at his school drive. He gets permission to go to the student parking lot and record some data. Later, he does some research about each model of car on the Internet. Then he makes a spreadsheet that includes each car’s model, year, color, number of cylinders, gas mileage, weight, and whether is has a navigation system.
Who are the individuals?
What variables did he measure?

14. Inference Drawing conclusions that go beyond the data at hand.
Using a sample group to discuss the population.

15. Activity – Airlines Discrimination
Each group of 4 will split into 2 to do the activity and 4 to discuss.

16. Activity – How Long is a minute

17. Homework
Page 7 (1, 3, 5, 6, 7, 8)