1. CHAPTER 1 Exploring Data
Introduction
Data Analysis:
Making Sense of Data

2. Data Analysis: Making Sense of Data
IDENTIFY the individuals and variables in a set of data
CLASSIFY variables as categorical or quantitative

3. What is Statistics?

4. What is going on here!
Take your piece of the graph and try to make one complete graph by finding the other pieces that go with your piece.

5. A) The months all OMHS students were born
Puzzle Exercise
Once you have completed your graph, discuss with the other members in your group what data your graph represents. Your options are as follows:
A) The months all OMHS students were born
B) The distribution of GPA’s at Harvard
C) The distribution of SAT scores in Maryland
D) The distribution of salaries for students right out of college

7. Is the data convincing?
One of the main things we will be looking at this year is how to determine whether or not we have enough data to make a conclusion about some hypothesis.

8. Stats Starts Here
According to 100% of people surveyed, this is the greatest class ever offered in college.
List of people surveyed: ME

9. The Exam (FICTIONAL DATA)
The class average last semester was a 94 on the final exam.
It was out of 500 points!!!!
A group of individuals averaged a 78% on an algebra exam……
The group of individuals were 7 year olds…
Or…the group of individuals were Algebra teachers!

10. Dream Job
The average salary at a company that has 25 employees is $8,500,000 per year.
Would you like to be hired by this company?
The CEO makes
$212,400,000 per year…
The other 24 employees
Average $4, per/year

11. The “W’s” To provide context we need the W’s Who
What (and in what units)
When
Where
Why (if possible)
and How
of the data.
Note: the answers to “who” and “what” are essential.

12. Data Analysis
Statistics is the science of data. Data Analysis is the process of organizing, displaying, summarizing, and asking questions about data.
Individuals
objects described by a set of data
Variable
any characteristic of an individual
Categorical Variable
places an individual into one of several groups or categories.
Quantitative Variable
takes numerical values for which it makes sense to find an average.

13. WEBQUEST Types of Variables

14. Dotplot of MPG Distribution
Data Analysis
A variable generally takes on many different values.
We are interested in how often a variable takes on each value.
Distribution
tells us what values a variable takes and how often it takes those values.
Dotplot of MPG Distribution
Variable of Interest:
MPG

15. How to Explore Data Examine each variable by itself.
Then study relationships among the variables.
Start with a graph
or graphs
Add numerical summaries

16. From Data Analysis to Inference
Population
Sample
Collect data from a representative Sample...
Make an Inference about the Population.
Perform Data Analysis, keeping probability in mind…

17. Data Analysis: Making Sense of Data
A dataset contains information on individuals.
For each individual, data give values for one or more variables.
Variables can be categorical or quantitative.
The distribution of a variable describes what values it takes and how often it takes them.
Inference is the process of making a conclusion about a population based on a sample set of data.