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

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

What is Statistics?

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.

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

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.

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

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!

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 $4,166.67 per/year

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.

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.

WEBQUEST Types of Variables

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

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

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…

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.