Statistics

Spring 2007

Introduction

Dr. Robb T. Koether Office: Bagby 114 Office phone: 223-6207 Home phone: 392-8604 (before 11:00 p.m.) Office hours: 2:30-3:20 MTWR

Other hours by appointment E-mail: rkoether@hsc.edu Web page:

http://people.hsc.edu/faculty-staff/robbk

The Course

The class meets in Bagby 106 at 1:30 - 2:20 MTWF.

The text for the course is Interactive Statistics, 3rd ed., by Martha Aliaga and Brenda Gunderson.

The web page for this course is at http://people.hsc.edu/faculty-staff/robbk/Math121

Course information is also available through Blackboard.

Introduction

Syllabus Lectures Assignments Page xi – Interactive Exercises Page xvi – Graphing Calculator

Grading

There will be Weekly quizzesSome Excel assignmentsThree testsA final exam

Grading

In the final average, these will have the following weights:

Category Weight

Average of quizzes & Excel 30%

Average of the tests 50%

The final exam 20%

Homework

The homework is the most important part of this course.

Learning mathematics requires gaining knowledge and understanding, but more importantly doing mathematics is a skill.

You should not expect to acquire a skill by listening to a lecturer talk about it. It takes practice.

Do all of the homework every day.

Homework

More importantly, do not put off doing the homework until the night before the quiz.

You will not be able to learn that much material in one night.

Most importantly of all, do not put off doing the homework until the day before a test.

By then it is too late to learn it.

Homework

At the beginning of each class meeting, I will spend up to 10 minutes working one or two homework problems in detail from previous assignments.

You may request a problem that you would like to see worked.

Of course, outside of class, I will help you with as many problems as I can.

Quizzes

Each Tuesday, after going over homework problems, there will be a 10-minute quiz.

The quiz will contain 1 to 3 questions taken from the previous week's homework assignments.

The problems will be copied verbatim from the book.

Excel Assignments

From time to time, as appropriate, I will assign small projects that will be worked using Microsoft Excel.

You will be allowed and encouraged to work in pairs on these assignments.

These will be graded with the same weight as the quizzes.

Tests

The test schedule is as follows:

Test Date Coverage

#1 Fri, Feb 16 Chapters 1, 2, 3, 4

#2 Fri, Mar 23 Chapters 5, 6, 7

#3 Fri, Apr 20 Chapters 8, 9, 10, 11

The Final Exam

The final exam will be cumulative. It will be given in this classroom at the time

stated in the exam schedule. Everyone must take it. It will not be rescheduled. Do not schedule a flight home before the

exam! You will lose your ticket.

Attendance

Attendance will be checked at the beginning of each class.

Two late arrivals will be counted as one absence.

The only valid excuses for missing class are An illness which includes a visit to the Health Center

or a doctor An approved college activity A true emergency Any absence excused by the Dean of Students

Attendance

Sending me an e-mail or leaving me a voice message does not excuse you from class.

Attendance

When assigning final grades, attendance will be taken into account.

Absences Action

0 – 2 Grade bonus

3 – 5 Neutral

6 – 8 Grade penalty

> 8 Withdrawal

Calculators

A calculator will be necessary for this course.

I strongly recommend the TI-83 or the TI-84.

The Honor Code

Quizzes, tests, and the final exam are pledged.

On Excel assignments you may work with a partner.

Classroom Etiquette During a lecture, you are free to ask

questions. It is polite to raise your hand first and wait

to be called on. You should not talk to other students while

I am talking. While working assigned problems in class,

you are free to talk to other students provided you are talking about the assigned problems.

Classroom Etiquette

Do not make leave the room during the class. If necessary, use the bathroom before coming to

class. If you are thirsty, get a drink before class.

Do not sleep in class. Do not work on assignments from other classes

during class. Do not read the newspaper during class.

The Scientific Method

Formulate a theory. Collect some data. Summarize the results. Make a decision.

The Scientific Method

Formulate a theory – Chapter 1. Collect some data. Summarize the results. Make a decision.

The Scientific Method

Formulate a theory – Chapter 1. Collect some data – Chapters 2 – 3. Summarize the results. Make a decision.

The Scientific Method

Formulate a theory – Chapter 1. Collect some data – Chapters 2 – 3. Summarize the results – Chapters 4 – 5. Make a decision.

The Scientific Method

Formulate a theory – Chapter 1. Collect some data – Chapters 2 – 3. Summarize the results – Chapters 4 – 5. Make a decision – Chapters 9 – 14.

The Scientific Method

Formulate a theory – Chapter 1. Collect some data – Chapters 2 – 3. Summarize the results – Chapters 4 – 5. Make a decision – Chapters 9 – 14. Theoretical underpinnings – Chapters 6 –

8.

Formulate a Theory

We are wondering whether a particular die is fair.

If it is fair, then the numbers 1, 2, 3, 4, 5, and 6 should come up equally often.

In particular, if we rolled the die 600 times, we expect to get each number 100 times.

Formulate a Theory

Or do we?

Formulate a Theory

The theory that the die is fair will be tested by posing it as a question with two competing answers.

Question: Does the distribution of observed rolls match what we would expect to see if the die were fair?

Formulate a Theory

The possible answers (yes and no) are stated more precisely as two competing hypotheses:“Null hypothesis” The die is fair.

Any deviations from the expected observation are due entirely to chance.

“Research hypothesis” The die is not fair. Any deviations from the expected observations are

due to the bias in the die.

Collect Some Data

So we roll the die 600 times and get the following results.

Number 1 2 3 4 5 6

Expected 100 100 100 100 100 100

Observed 97 97 96 90 102 118

Two Possible Explanations

There is a discrepancy. Can it be explained by chance?

Summarize the Results

We use the TI-83 or TI-84, and compute a special quantity:

2 = 4.62.

Summarize the Results

Use the TI-83 or TI-84, and compute a special quantity:

2 = 4.62. If the die really is fair, then theory says that

we expect this calculation to yield the value 5, plus or minus a bit.

Make a Decision

Theory says that if the die is fair, then this value should be less than the critical value of 11.070.

Since 2 is less than the critical value, we conclude that the “null hypothesis” is correct:

The die is fair.

An Important Question

Does this procedure prove that the die is fair?

An Important Question

Does this procedure prove that the die is fair?

We may that it “proves” it statistically, but it does not prove it logically.