Statistics 111/130
Probability and Statistical Inference/Probability and Statistics for Engineers

syllabus, course policies, office hours, and general information

Basic Information

  • Lecture Times and Location:  Mondays and Wednesdays, 3:05 - 4:20 PM,  in LSRC B101.


  • Lab Times/Location: Econ labs are on Fridays at 8:30-9:45 a.m., 10:05-11:20 a.m., 11:45-1:00 p.m., and 1:25-2:40 p.m.; the Engineering lab is on Thursday at 3:05-4:20 p.m. All labs are in Old Chem 101.  


  • Instructor: Professor David Banks,  210A Old Chemistry Building,  919-684-3743,


  • Instructor's Office Hours:   Sundays, 1:00-2:30 p.m. in the Old Chemistry Building Building, room 116.   Note: The instructor will not answer technical questions by email---please raise these during office hours or at the start of class or with a TA. (People: I regret this. But each semester has gotten worse, with more and more students asking me to email them long individual replies with detailed explanations. I am very sorry that it is not possible to continue to be available in this way.)


  • TAs' Office Hours:  TA office hours and locations are listed in this spreadsheet. But Mabel Zhang has office hours on Tuesday from 10:30-11:30 and on Thursday from 5:00-6:00, Heather Matthews has office hours on Monday from 10:00-11:00 and on Tuesday from 12:00-1:00, Austin Jia has office hours from 2:30-4:30 on Sunday, Eden Huang has office hours from 6:00 to 8:00 on Monday, and Liuyi Zhu has office hours from 2:00-3:00 on Wednesday and 5:00-6:00 on Friday.


The course schedule is posted on the website. The course will cover probability, up to double integrals for bivariate densities. Inference includes Bayesian and maximum likelihood estimates, and traditional and bootstrap methods for confidence intervals. Hypothesis testing is covered in multiple ways---parameter tests, goodness-of-fit, and ANOVA, as well as power. Regression includes simple, multiple, nonlinear and nonparametric regression. We cover two-way ANOVA and fractional factorial designs. We also briefly discuss risk analysis and decision theory.


The recommended, but optional, text is Probability and Statistics (4th edition) by De Groot and Schervish, published by Addison-Wesley (ISBN 10:0-321-50046-6, price $132.99).   Finding a good book is always a problem---none of the available texts is fully satisfactory. In general, this is a technically strong introductory book, but this course will supplement its coverage at several points. The book is worth keeping for reference in future courses and later life.

Course lectures will be posted on the class website the day before the lecture.   You are encouraged to print these out and bring them to class---that way you can focus on the material rather than taking notes.   To save trees you can use some special print options. For PCs, use (1) Print - ePrint; (2) Properties (just to the right of the printer selector): a. "Print on both sides" b. "Pages per sheet" (Four pages per sheet works well for the lecture notes) c. OK; (3) OK/Print.   For Macs, use (1) File - Print; (2) Click on the box that says "Copies and Pages"; (3) Select "Layout"; (4) Select "Two-sided Printing" (long-edge is usually preferred); (5) Properties - "Pages per sheet" (four pages per sheet works well).


We shall use the statistical software package Stata during the economics labs and Matlab in the engineering labs, and all students are welcome to use R, or any other package they prefer.  Stata is the only package used by Duke's Economics Department, and since most students in STA 111 are econ majors, this may be your most efficient choice.  Many econ majors purchase and install Stata on their laptops, but it is available for free in OIT computer clusters. 


For every lecture, you will need a simple calculator for quizzes, exams and homework.   Graphical capability is not required, and questions are worded so that advanced calculators confer no advantage.

Advice for Success in Statistics 111


The best way to learn statistics, or any quantitative subject, is to work problems.  Although you usually won't have to turn in problems from the book, working these at home on a regular schedule will significantly improve your understanding of the material.  Also, the homework and exams (discussed below) are based on the concepts reviewed by the problems in the text, so a solid understanding of these problems increases the chance that you will earn a high grade in the course.  

Most sections in the text are followed by a set of exercises.  I recommend working these as you read.  There are also review exercises at the end of most chapters; doing these a few days after reading the chapter will consolidate your understanding.


Students who work in groups in quantitative courses learn more and enjoy the course more than those who work alone (see the studies by Richard Light at Harvard University). Also, if your schedule prevents you from coming to office hours, you will definitely want to have people in your group who can attend.


Students who succeed in Statistics 111 typically put in at least 6 hours of work per week outside of the classroom.  You should set up a realistic study schedule in which you spread your work over the week.  It is a poor idea to rely upon cramming the night before an exam.

Finally, please use us, the TAs and instructor, for help when you get stuck.    We are allies in your assault upon statistics. 

Graded Work

Graded work for the course will consist of quizzes, homework, lab work, and four exams. Your final grade will be determined as follows:

Exams 1-4

20% on the best score, 15% on the second and third best, 10% on the worst





Lab Work


There will be no final exam for this class during Duke University's exam period at the end of the semester.

Missed homework, quizzes, or lab reports can only be excused under exceptional circumstances. For short-term illness, please send the instructor the standard Duke form. Except in emergencies, all other absenteeism must be approved in advance (e.g., an athlete who must miss class may be excused by prior arrangement for specific days).   For emergencies, email notification is needed at the first reasonable time.

If a student has an excused absence from an exam, quiz, homework, or lab, then the missing grade will be imputed by the average of all other corresponding grades on exams, quizzes, homeworks, or labs (without any dropped scores).

Each exam, quiz, homework, or lab will receive a letter grade. An 'A+' corresponds to a score of 12, an 'A' corresponds to 11, an 'A-' is a 10, a 'B+' is a 9, and so forth. The final grade in the course is determined by the weighted average (as per the table above) of these scores. Breakpoints for grades occur at the halfway points. For example, the lowest possible average that gives an 'A-' for the semester is 9.5.

Descriptions of Graded Work


You will download homework assignments from the class website. There will be a homework assignment for almost every week, and it must be turned in at the beginning class on the date indicated. The homework component of the final grade is found by dropping the lowest homework grade and averaging the rest.

Lab assignments:

Almost every week, there are data analysis problems to be completed in lab.  Labs provide hands-on experience in analyzing data under the guidance of the TAs.  The labs teach you how to apply the skills discussed in lectures and readings. You must attend your scheduled lab except when given prior permission by the instructor or a TA to complete the lab in another section.  This is necessary because space in the labs is very tight.

You are graded on lab reports that must be turned in by the end of the assigned lab period.  The lab component of your final grade is found by dropping the lowest lab grade and averaging the rest.   


There will be short in-class quizzes in almost every lecture.   The purpose of these is to help students realize instantly what parts of the current material they have mastered and what parts are unclear. Quizzes will focus on difficult material from previous lectures, easy material from the current lecture, and the assigned reading for the day. The quiz component of your final grade is found by dropping the two lowest quiz grades and averaging the rest.   

Academic Honesty

You are expected to abide by Duke's Community Standard for all work for this course.  Violations will be reported to the Dean of Students for adjudication; the minimum penalty for cheating is failure in this course. 

For homework, you are allowed to discuss problems in general, but the final solution and write-up must be your own.   For in-class exams and quizzes, you are required to work alone and for only the specified time period.  For labs, you are allowed and encouraged to help each other, but each person must complete the lab report on their own.   

Procedures for Requesting a Regrade

Every effort will be made to mark your work accurately.    We are on your side, and want you to receive every point you have worked to earn.   However, sometimes grading mistakes happen.  If you believe that an error has been made, return the paper to the instructor within two weeks, stating your claim in writing.

The following claims will be considered for re-grading:

(i)    points are not totaled correctly;
(ii)   the grader did not see a correct answer that is on your paper;
(iii)  your answer is the same as the correct answer, but in a different form (e.g., you wrote a correct answer as 1/3 and the grader was looking for 0.333);
(iv)  your answer to a free response question is essentially correct but stated slightly differently than the grader's expectation.

The following claims will not be considered for re-grading:

(v)   arguments about the number of points lost;
(vi)  arguments about question wording.

Considering re-grades consumes time and resources that TAs and the instructor would rather spend helping you understand material.  Please bring only claims of type (i), (ii), (iii), or (iv) to our attention.