Probability and statistics are important subjects because
so much of what we take for granted is based on them. The
insurance and gambling industries would not be possible
without probability theory. Much of modern finance relies on
probability and statistics. And much of modern science, both
physical and social, would grind to a halt without the tools
of statistical analysis.
Given its importance, it is unfortunate that so many
students find statistics a difficult course. Some find it
challenging because they lack basic math skills. Even though
an introductory-level statistics course does not require
mathematics beyond what a high school freshman or sophomore
should be able to do, many adults and college students do
not have even that level of math competence. Others find it
difficult because they try to get through the course with
brute memorization. Statistics is a problem-solving subject,
and a strategy of memorization will not work well when
problem-solving skills are required.
Statistics is a subject that tries to make students think
in new ways, to see the reality around them from
perspectives they have not used before. Once you understand
statistics, you should see the world in ways you presently
do not know exist.
A good introductory course should help you become a
competent consumer of statistical information. As a
competent consumer of statistical information, you will be
able to understand what an author is trying to do when that
author gives you the results of a statistical analysis.
While taking an introductory course, you will learn to do
some simple statistical analysis, but you will not learn
enough to be a competent producer of statistical
information. That requires additional study.
Even though probability and statistics are mathematical
subjects, the emphasis in an introductory course should not
be on the mathematics but on the intuitive understanding
that is behind the mathematics. Instructors attempt to help
students get to that intuitive understanding with a generous
dose of problems and assignments worked with computer
statistical packages. However, there is no magic way to get
the student to the "ah-ha" moment when suddenly it all
starts to make sense.
I taught introductory statistics for college students off
and on for almost 40 years. During that time I wrote many
homework assignments and many quizzes and tests. The
problems from these assignments, quizzes, and tests form the
major part of this website. Statistics is something you
learn by doing, not by passively reading. I have added short
introductions and explanations but these short explanations
are not a substitute for a real textbook. This site will
never be developed enough to serve as an independent
textbook, but it may be able to serve as a supplement for a
variety of textbooks.
I apologize in advance for the typos and errors that
remain in this material. If you find some of them, please
tell me about them at schenk at saintjoe.edu. Also, though I
have included answers for some of the questions, there are
many problems and questions that still do not have an answer
key. If you work them and would like me to check them, I
will if I can use the results as part of an answer key.
Finally, I am open to suggestions for improvements as long
as the benefits exceed the costs.
(I intend that only material I wrote and developed appear
on this website, but it is possible that a few items that I
used from old testbanks or textbooks for homework or quizzes
may be included. If you find anything that appeared in
another text, tell me and I will remove it.)