Stats I - Chapter 1
May 29 – Quiz #1 – 15 m/c
June 5 – assignment 1 due
June 23 – Midterm exam chapter 1-9
July 17 – Quiz #2
July 24 – assignment 2 due
Chapter 1, 2, 3, 5 – m/c
Chapter 6 – most difficult chapter
What is Statistics?
Statistics is a way to get information from data.
The word "statistics" is often used to mean a body of data, but in mathematics, the word also refers to
the methods of extracting information from data.
Data – collection of information
DATA STATISTICS INFORMATION
Statistics is a tool for creating new understanding from a set of numbers.
Example: 2.6 Stats Anxiety
A student enrolled in a business program is attending the first class of the required statistics course. The
student is somewhat apprehensive because he believes the myth that the course is difficult.
To alleviate his anxiety the student asks the professor about last year’s marks.
The professor obliges and provides a list of the final marks, which is composed of term work plus the
final exam. What information can the student obtain from the list?
- Counting the 80s, 60s, etc. marks to figure out the average of 80 students’ marks
Mean (average mark) – highest mark less the lowest mark
Median (mark such that 50% above and 50% below)
Mean = 72.67 Median = 72
Is this enough information?
Are most of the marks clustered around the mean or are they more spread out?
Range = Maximum – minimum = 92-53 = 39
The branch of study called Descriptive Statistics is concerned with:
- organizing and,
- presenting information
…in a meaningful way by summarizing data numerically and displaying it in various types of charts and
- Graphical Techniques (Chap 2 & 3)
- Numerical Techniques (Chap 4)
The actual method used depends on what information we would like to extract. Are we interested in…
- measure(s) of central location? and/or
- measure(s) of variability (dispersion)?
- Descriptive Statistics helps to answer these questions…
- Inferential Statistics is a body of methods used to draw conclusions or inferences about
characteristics of populations based on sample data.
- A population is the group of all items of interest to a statistics practitioner. It is frequently very
large (may be infinitely large).
- A descriptive measure of a population Which of the following statement is false? Population and parameter
- sample is a set of data drawn from the population – small size compare