1. Chapter 1: Introduction
Statistics Day 1
Chapter 1: Introduction

2. Types of data!
Categorical -- also called count data. Simply records which category a person or thing falls.
Quantitative - (numerical) data – numerical values for which arithmetic operations make sense. You can find the arithmetic average of this data.

3. AP TEST CHECK!!

4. Categorical vs. quantitative variables
Would the variable “monthly rainfall in Michigan” be considered a categorical or quantitative variable?
categorical
quantitative

5. Categorical vs. quantitative variables (answer)
Would the variable “monthly rainfall in Michigan” be considered a categorical or quantitative variable?
categorical
quantitative

6. Categorical vs. quantitative variables
If we asked people to report their “weight,” would that variable be considered a categorical or quantitative variable?
categorical
quantitative

7. Categorical vs. quantitative variables (answer)
If we asked people to report their “weight,” would that variable be considered a categorical or quantitative variable?
categorical
quantitative

8. Categorical vs. quantitative variables
We then asked people to classify their weight as underweight, normal, overweight, or obese. Would this variable now be categorical or quantitative variable?
categorical
quantitative

9. Categorical vs. quantitative variables (answer)
We then asked people to classify their weight as underweight, normal, overweight, or obese. Would this variable now be categorical or quantitative variable?
categorical
quantitative

10. Categorical vs. quantitative variables
What type of data is produced by the answer choices for this question?
categorical
quantitative
How many times have you accessed the Internet this week?
None
Once or twice
Three or four times
More than four times

11. Categorical vs. quantitative variables (answer)
What type of data is produced by the answer choices for this question?
categorical
quantitative
How many times have you accessed the Internet this week?
None
Once or twice
Three or four times
More than four times

12. Example Question 1 State Number of family Members Age Gender
Marital Status
Total
Income
Travel time
To work
Kentucky 2 61
Female
Married
21000 20
Florida 6 27
21300
Wisconsin
Male
30000 5
California 4 33
26000 10
Michigan 3 49
15100 25
Virginia 26
25000 15
Pennsylvania 44
43000 22
Never Married/single
3000 1 30
40000
New York 34
Separated 40

13. Distribution
The distribution of a variable tells us what values the variable takes and how often it takes these variables.

14. Example 2
Example 2: 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. Late he does some research about each model of car on the internet. Finally, Jakes makes a spread sheet that includes each car’s model, year, color, number of cylinders, gas mileage, weight, and whether it has a navigation system.
Who are the individuals in Jake’s study?
What variables did Jake measure? Identify each as categorical or quantitative.

15. Statistical Inferences
uses collected data to make generalizations about the entire group. Produces answers to specific questions and a statement of how confident we can be that the answer is correct.
(NOTE: We cannot predict with absolute certainty! We cannot make predictions about individual cases!)

16. Activity 1
Hiring Discrimination

17. Assignment
Page 7 1,2,3,7,8