Introduction To Statistics
Section 1.1
Leading Questions
What is statistics? What type of math is used in statistics? Why do we use statistics? Where are stats used in the world? What jobs use stats?
Definitions
Statistics – the study of how to collect, organize, analyze and interpret numerical information from data
Individuals are the people or objects included in the study
A variable is the characteristic of the individual to be measured or observed.
Types of variables
Quantitative – has a value or numerical measurement for which operations such as addition or averaging makes sense Ex. Scale of 1 – 5; age; weight; distance;
height; etc.
Types of variables
Qualitative – describes an individual by categorizing or grouping Ex. Male vs. female; hair color; city;
religion; type of building; yes or no; etc.
Types of data
Population data – the variable is from every individual of interest
Sample data – the variable is from only some of the individuals of interest.
Class Example
What is a study that someone would conduct and use our class to interview for information toward the study.
Name the individuals and variables, is it qualitative or quantitative; Who would be the pop. And who would be the sample?
Guided Exercise 1: pg. 6
Television station QUE wants to know the proportion of TV owners in Virginia who watch the station’s new program at least once a week. The station asked a group of 1,000 TV owners in Virginia if they watch the program at least once a week.
G.E. #1 Questions
Identify the individuals of the study and the variable
Do the data compromise a sample? What’s the population?
Is the variable qualitative or quantitative?
Give an example of the other that could be of interest.
Levels of measurement
Nominal – names only Bill is a Baptist
Ordinal – can be ordered, but the differences are meaningless Sara is 7th in her class
Interval – meaningful difference between data value, but not a starting point The temperatures in July
Ratio – includes an inherent zero Sam earned $567 in May
Guided Exercise #2: page 9
Give the level of measurement for each of the following. The senator’s name is Sam Wilson. The senator is 58 years old. The senator was elected in 1980, 1986,
1992, 1998. The senator is married.
Guided Exercise #2: page 9
A leading news magazine claims the senator is ranked 7th for his voting record on bills regarding public education.
His total income last year was 878,314.19.
Homework
page 10 #1, 2, 4, 6
