2025 Math/Stat 242:
Introductory Statistics
This is a subpage of the Math/Stat 242 Course page. If you need overall syllabus info about Math/Stat 242, click here.
This course meets in Morken 214
M, W 12:15 - 1:45 pm OR
M, W 2:00 - 3:30 pm
Student hours are
M, W, F 10:30-11:15 am;
Th 11:30-12:15pm;
& by appointment! (in person or virtual)
Office hours next week: Tuesday 11am-noon
Last Coffee/Fruit/Donuts is Friday 11:45am in ERB.
Final Exam:
12:15pm group: Tuesday, December, 9th 1:15 p.m. - 3:15 p.m.
2pm group: Wednesday, December, 10th 1:15 p.m. - 3:15 p.m.
Late HW due by Dec 10.
Office Hours:
Thursday 11:30-12:15
Friday 10:30-11:30 (in and out; grad picture time)
Tuesday 11am-noon, and by appointment
Finish HW 08 (due today)
Optional take-home exam (due Friday)
Work on Project (due next Thursday; one per group)
Project Group evaluation (submitted individually, due next Friday)
Send NJ email confirmation of course evals when complete (due next Friday)
Type I and Type II Error
Introduce ANOVA: (Analysis of Variance)
Review again Overview of basic methods notes
types of variables for ANOVA
Discuss null and alternative hypotheses
Projects: I expect to have about 30 min in class today and Wednesday
Projects Due Finals Week
Group Evals due Finals Week
Course Evals confirmation due Finals Week
Final Exam:
12:15pm group: Tuesday, December, 9th 1:15 p.m. - 3:15 p.m.
2pm group: Wednesday, December, 10th 1:15 p.m. - 3:15 p.m.
Just Let NJ know if you want to take your final during the other section's exam time.
Final Exam Study materials:
Finish HW 08 (due Wednesday)
Work on Project
Send NJ email confirmation of course evals when complete
Later this week: (optional take-home exam)
Regression Follow up to Last lesson/ HW help
Formal Procedures (Ho; Ha; etc.)
Conditions to check for:
Linearity
No outliers
Nearly normal residuals
Homoskedasticity
Testing Linear Models in R
R code will be posted here
Chi Square Tests
Null and Alternative Hypotheses for a Chi-Square Test.
Example: In the table below, is variable 1 reasonably independent of variable 2? How do you know?
Would you expect this Chi-Square test to have a large or small p-value and why?
Chi Square Test practice:
Throughout human history, romantics, poets, balladeers and songwriters have celebrated the idea that there’s just one true love for every living soul. Does education appear to have a significant association with whether Americans agree that they have only one true love?
Just based on your intuitions, do you think there will be a significant association?
What are the null and alternative hypotheses?
Use these data to calculate a p-value in R.
How do we interpret the p-value?
How do we conclude?
Caveats (Examine Conditions)
If interested: Calculations for the chi-square statistic
Project Time
Have a great THANKSGIVING!
Wednesday's class:
12:15pm group: I'm not allowed to cancel class but it will be time to get help on project and/or HW due Monday.
2pm group: no class (Thanksgiving)
Let NJ know if you want to do the other final exam
HW 08 due today
Final Exam Study materials:
Make inferences based on your data
Agenda:
Project Time
Comments
Connection between correlation & slope.
Formal Procedures (Ho; Ha; etc.)
Testing Linear Models in R
Conditions to check for:
Linearity
No outliers
Nearly normal residuals
Homoskedasticity
R code will be posted here.
Have a great THANKSGIVING!
Wednesday's class:
12:15pm group: I'm not allowed to cancel class but it will be time to get help on project and/or HW due Monday.
2pm group: no class (Thanksgiving)
Final Exam:
12:15pm group: Tuesday, December, 9th 1:15 p.m. - 3:15 p.m.
2pm group: Wednesday, December, 10th 1:15 p.m. - 3:15 p.m.
Just Let NJ know if you want to take your final during the other section's exam time.
See flyer below: Internships support
See flyer @ right: Modeling contest signup sheet
We are Skipping project part 4b. Project Part 5 is on G.C.
Next week will have 2 lessons (anova & Chi-square tests) & the rest will be project time.
HW 08 due Wednesday 11/26 but no penalty for handing it in the following Monday 12/1 - this is the last HW
Take-Home Exam (Optional) Coming soon, Due 12/5
If it helps your grade, it will count for about 20%.
Final Exam Study materials:
Use an applet to calculate a p-values for a test of correlation between two variables.
Interpret the meaning of the above.
Use a p-value to conclude whether an observed association between two quantitative variables is reasonable to attribute to random chance.
Agenda:
Group processing time. In an email to NJ:
What is working well in your group?
What is the biggest challenge in your group?
What can you do to take steps toward challenges in your group? (Do that now, if you can!)
What support do you need from NJ regarding your group/project?
Reminder of where we are on the overview of basic methods
Reminder to be respectful of diverse views on the role and scope of our military.
Some have lost family members in service to our military
Some are seeking careers in service to our military
What do you know about the correlation coefficient?
Lesson 16 - Inference for Correlation (notes)
Here is the link to the data
Here is the link to the applet
If time: work on Project in Groups.
See Peace Scholars info. (far below)
Consider participating in the mathematical modeling contest (see flyer @ lower right).
No HW this week; just Project part 4a due today.
Use R to Calculate p-values and confidence intervals for 2-samplet-tests.
Correctly interpret the results from above
Agenda:
Lesson 15: two-sample t-tests (notes)
Project time
This program is a great opportunity for any students interested in peacebuilding and community activism. It is also very important to note that travel, lodging, and meals related to the Peace Scholars summer study are paid for by generous donors to PLU. The fully-funded seven-seek summer program in Oslo, Norway, includes:
Transfer credits for both the Peace Scholars Seminar and the International Summer School in Oslo course
Engaging lectures and research on peacemaking and policy
Meetings with Oslo-based organizations and leaders in global peace initiatives
Cultural activities and excursions around Norway with students from around the world
Two Peace Scholars will be selected from a pool of applicants by the PLU Peace Scholar Committee. The deadline this year is February 1st. Please have interested students contact the Wang Center at wangcenter@plu.edu or at X7678. For more information and to apply, students should be directed to the program website at https://www.plu.edu/peace-scholars/.
Internships talk on next Wednesday (see flyer @ right)
Project Part 4 has two parts.
Reminder: Peer ratings for the group project are coming! link
Econ/Environment Interest? Come listen to Derek Nixon, Nov 21, 12:15-1:15pm in Admin 101.
Project Part 4a (individual portion) due Wednesday.
this is just a screen shot of your data viz & code.
Agenda:
What is your favorite month of the year and why?
NJ does a better demo of descriptive statistics for 2 categorical variables.
Plot selection & Assignment
Determine Plots
Discuss in groups: for each research question, what plot(s) would give us insight into what is being asked? Record the type of plot next to your research question in your data proposal spreadsheet.
Assign group members in order, according to their favorite month, to ABCD(E)
Write student name next to the RQ & type of plot in your spreadsheet
Data Cleaning time!
True data cleaning typically happens in R or another command-line program. (You can learn about that in Math/Stat 348!) For this class, we'll do some informal stuff in Google Sheets.
Coffee, Fruit and Donuts on Friday
Internships talk on next Wednesday (see flyer)
Project Part 4 has two parts.
Reminder: Peer ratings for the group project are coming! link
If you have a dysfunctional group, what are you doing to help it?
If you are not fully participating, how can you contribute?
Econ/Environment Interest? Come listen to Derek Nixon, Nov 21, 12:15-1:15pm in Admin 101.
HW due tomorrow
Project Part 4 due next week; stay tuned until after Monday's class.
Learn how to compute and interpret basic data visualizations in R.
Agenda:
HW questions
Brief intro: script files vs. quarto files
Lesson 13 - basic plots in R.
Hold off on Project Part 4 until Monday. :)
Coffee, Fruit, & Donuts on Friday
Collect project data by Wednesday
Nov 19: brown bag about internships
Now is the time to be applying for summer internships!
Equitable Data Science in Adolescent Development paid internship
Keep an eye on SIBS (not updated for 2026 yet):
Meghan recommends this opportunity at UW Madison
No Quiz due tomorrow (work on finishing collecting your data)
Collect data by Wednesday
HW due Thursday
Explore population distributions that do and do not satisfy the CLT conditions
Discern whether the CLT conditions are met for inference about means.
Agenda:
Shvets, A. (2020). Woman in Face Mask Checking Thermometer Licensed under Pexels. Retreived from Pexels.
New groups seating Chart 12:15 class, 2:00 class
HW due Thursday
Collect data by Wednesday of next week
Use R to Calculate p-values and confidence intervals for t-tests.
Correctly interpret the results from above.
HW questions
Intro to packages in R
Start Lesson 12: t-tests (notes)
NJ is behind on project grading; thanks for your patience
PLEASE correct error in Lesson 10: the example code on the last page for the prop.test() example is incorrect: 1602 should be 1070.
Food insecure? Here are resources to help! Check out:
New groups coming soon, according to project groups. Let me know if you have location needs to support your learning. (Please don't assume I remember!)
Please don't start data collection until you have feedback on Project Part 2!
Quiz 07 on G.C. due tomorrow
HW due Thursday
Work on data collection after getting the OK from NJ
Detect the difference between a change in absolute or relative risk
Understand that a Relative Risk chance can appear large even though it is actually very small
Explain how manipulative reports of change in risk can harm public good if not reported appropriately.
Lesson 11: Absolute vs. Relative Risk (notes)
Work on HW_06 and
(If applicable) Touch base with NJ regarding sampling plans & research questions
PLEASE correct error in Lesson 10: the example code on the last page for the prop.test() example is incorrect: 1602 should be 1070.
Food insecure? Here are resources to help!
The PLU Pantry is available for all members of our campus community who need food assistance.
Trinity Lutheran Church also operates a food pantry
Lake City Community Church food bank
You can vote in the Reike Photo Contest! https://forms.gle/4NxZk8oM4LudNLWH7
Mole Day—Nov 3
New groups coming soon, according to project groups. Let me know if you have location needs to support your learning. (Please don't assume I remember!)
Please don't start data collection until you have feedback on Project Part 2!
Project Part 2 due tonight
Email NJ if you need help finding a group for the final project.
If your group <4 NJ may add people to your group.
NJ's reflections/apologies on Project Part 2.
In groups:
What is your (realistic) dream job & why?
Assign roles (TBA)
Use the ISI applet to finish Lesson 10
(Review) Contagious Yawns Example
Discuss Lesson 10: Two-sample z tests (notes)
If time: Chance to work on Project Part 2
NJ out sick today
Class and office hours today cancelled.
You can vote in the Reike Photo Contest! https://forms.gle/4NxZk8oM4LudNLWH7
Mole Day—Nov 3
New groups coming soon, according to project groups. Let me know if you have location/personnel needs to support your learning.
Today: Math Advising Party (see flyer @ right)
Project Part 2 due Wednesday
Email NJ if you need help finding a group for the final project.
If your group <4 NJ may add people to your group.
Agenda:
NJ is out sick today
Students may use this time to meet together and complete Project Part 2.
Thanks, Rorie, for the sampling comic (@ right)!
Mole Day—I hear it's awesome—Nov 3 (see flyer below)
If you worked in a group on Project Part 1 and received a 0 grade, please just let me know who submitted on your behalf.
New groups coming soon, according to project groups. Let me know if you have location/personnel needs to support your learning.
Project Part 2 due next Wednesday
Email NJ if you need help finding a group for the final project.
If your group <4 NJ may add people to your group.
NJ's summary of Midterm Feedback
In groups:
What is your favorite holiday, and how do you celebrate it?
Assign roles (TBA)
Finish Lesson 09
Review of prop.test() function in R.
Lesson 10: Two-sample z tests (notes)
(If time) Contagious Yawns Example
Intro/Review: Quarto files (in R)
Please take care of yourself and your community!
NJ's source of support: https://lc3.com/
I'm happy to chat about non-statistics stuff or point you to resources
Advising week: reach out to your adviser to schedule a meeting!
NJ is happy to meet with anyone interested in statistics minor, Data Science major or minor, Math major or minor, and Applied Math major.
Upper Division Math Classes Teasers: Wednesday in Morken 214 11:45-12:15. (See flyer @ right) Please come!
Complete Mid-term feedback (on G.C.)
Quiz 06 (on G.C.)
Start thinking about who you'd like to work with on the project (need at least 1 partner; NJ recommends groups of 3 or more.
Must be in your same section (so you can work together during class)
Consider availability outside of class.
Project Part II coming soon.
How do you feel about scary movies?
Review sampling methods.
Two more sampling methods
Volunteer Response (not recommended!)
Multistage (a great option!)
Lesson 09: Overview of basic tests (notes)
(If time) Lesson 10: Two-sample z tests (notes)
Submit Project Part 1. (one per group) on G.C.
Complete Mid-term feedback (on G.C.)
In groups:
Who is your favorite person right now and why?
If you were trying to pick a group of 5 "representative" trees from the image below, what 5 trees would you choose?
Discussion of HW 05
Discuss the quiz question #2 given below
Change your answer if you like!
Lesson 1X: sampling methods (notes)
Finish project part 1 and submit on Google Classroom
Some groups needed to adjust/move: seating Chart 12:15 class, 2:00 class
HW 05 due today!
Quiz Due tomorrow
Project Part 1 due Thursday
Mid-Semester Feedback Due Friday
Agenda:
How to view your grades in Google Classroom
In groups:
NJ discusses the formula for calculating a CI.
Start Project: Part 1
@ 10 min left: Comments on the Exam
Return Exams
HW 05 due Monday (in-class time today; see note above)
Coming soon: Mid-semester feedback
Agenda:
New Groups
Establish roles in groups
how to refer to you
If you could teleport anywhere right now, for 1 hour, where would you go? Why?
If you could bring one person, who would you bring and why did you choose them?
Group Processing
What are your strengths working in groups?
What are your weaknesses working in groups?
How can your group best support you/help you engage?
exchange contact information
Causal Claims vs. Claims of Association (NJ slides)
Work on HW 05 together in groups.
Agenda:
NJ's Reminder not to use cell phones / not to check cell phones/ turn them off now
Please put computers away. If during the exam you decide you would like to use R, you may log into a classroom computer at that time.
Interpret the (purpose and) meaning of a confidence interval
Calculate the confidence interval for a population proportion using a series of hypothesis tests
Navigate the relationships between sample size, the width of a confidence interval, and the confidence level
Agenda:
(If time): Discuss how to calculate a confidence interval using R
(If time): CI interval practice (link).
(If time): Discuss how to calculate a confidence interval by hand.
Take-home exam due Oct 1.
This is a hard deadline! Scores of 0 once I release scores/solutions to the class!
In-class Exam 1: Oct. 6.
In-class Exam could be tougher than the take-home.
As you study, if you want my solutions to one of the activities, please ask!
No quiz this week
Exam 1 Review is here.
You can thank Alex!
...And tentative solutions are here.
Take Home Exam (due Wednesday).
Use z-scores to assess whether an outcome is unlikely
Discern whether a question asks for a confidence interval or a hypothesis test
Agenda:
Take-home questions?
Discuss standard devation, z-scores (slides): What is a big deal?
HW 04 Due Thursday, next week!
Take Home Exam (coming soon on G.C.)
Expected release tomorrow.
Let NJ know if Oct 6 is a conflict for Exam 1
Agenda:
In Groups:
Your name and how to refer to you
If you had to give a TED talk right now (wiht no preparation), what would it be about?
Discuss questions on the quiz
12:30 class: functions, arguments in R (slides: 02 Script Files & basics)
Lesson 05 (notes)
Homework Questions.
Quiz (open today at 3pm, due tomorrow)
HW 04 tentatively Due Thursday, bring questions to class on Wednesday!
Let NJ know if Oct 6 is a conflict for the in-class exam.
Agenda:
New Groups:
Your name and how to refer to you
Choose your favorite:
In groups: Summarize what we've done so far in Lesson 04
Finish Lesson 4 (notes)
Intro to R (slides: 01 Intro, 02 Script Files & basics)
Lesson 05 (notes) - you need some of this for HW 04
We will use R on Monday
HW 3 Due Thursday
Email NJ if you have requests regarding groups
Download R/ R Studio
Discern when the research question calls for a one versus a two-tailed test
Calculate the p-value for a 2-tailed test
Agenda:
Quiz discussion
HW questions
P-value practice
More p-value practice: (link)
Lesson 4 (notes)
We will likely start using R next week. (Downloading it is on your to do list)
Classroom computers have R/R-Studio if needed.
Quiz 03 is on GC (due tomorrow)
HW 03 is on GC (due Thursday).
Take a look and bring your questions to class on Wednesday!
Email NJ by 7pm Sunday if you have requests for seating for the next groups!
Proximity to window or door
Position relative to the screen
Personnel to avoid to support your learning (I don't need details)
Due Soon (next week?)
Read Modern Dive first few sections of Chapter 1 (Stop when it says: 1.2 How do I code in R?)
Download (or update) R on your computer
Download (or update) R-Studio on your computer
Apply statistical tests in ways that can make social change
Set up hypothesis test NOT with 50-50 model
Calculate a p-value and use it to conclude about a statistical question.
Agenda:
Seating Chart 12:15 class, 2:00 class
Reike photo contest (see flyer @ right)
Coffee Donuts Fruit (free!) in ERB on September 15 11:45am-12:15pm
NJ is the "Director of Data Science" at PLU. Come see me if you are interested in:
Minor in statistics
Minor in Data Science
Major in Data Science
Major in Applied Math
Major in (Pure) Math
HW due Friday @ 3pm
Agenda:
In Groups:
Share/remind us how we should refer to you
What is your "theme song" for today?
Quiz from Tuesday: check in with group about any questions you had.
Parameter vs. Statistic practice (link)
Finish Lesson 02 - Lesson notes
Homework 02 questions
If time: Start Lesson 03: A Discrimination case (notes)
Seating Chart 12:15 class, 2:00 class
Please let me know if I refer to you incorrectly
12:15 pm class: do you want a smaller class size? Join the 2:00pm class!!!
ERB (Math Center) is across from NJ's office & open to all students taking math!
Naufal's contact info:
Let me know if you want to use electronic copies of the notes
Email NJ food allergies
We may adjust the due date of HW to Thursday @ 3pm.
Quiz 2 open @8am Monday, due Tuesday 3pm
Check out HW2 and bring questions to class on Wednesday!
HW 2 open @8am on Monday, due Friday @ 3pm
Agenda:
Group Formation/Processing:
Share/remind us how we should refer to you
Share about your favorite pet & why you liked it. (If no pets? Share your Favorite family member or friend)
Syllabus Quiz
12:15pm class: complete Syllabus Quiz
2:00pm class: double check answers b/c there are some incorrect ones!
More intro to hypothesis testing: Buzz and Doris.
01 -Lesson Notes.
If time: formalizing the process
02 - Lesson notes
If time: Hypothesis Testing Practice (link)
Seating Chart 12:15 class, 2:00 class
Welcome! I am Dr. Justice!
Important websites:
How to reach the syllabus
How to reach this Weekly Content Page
Best way to reach NJ is via email
If you have a question about coursework be sure to include the question prompt in the email.
Student (Office) Hours:
M, W, F 10:30-11:15am
Th 11:30 am-12:15 pm;
& by appointment! (in person or virtual)
Intro Naufal: naufal.alavi@plu.edu
Due by Thursday (7:30pm):
Join Google Classroom
Information Sheet (on G.C.) (~10 min)
Read Syllabus
Syllabus Quiz (on G.C.) (~10 min) - postponed to Monday for the 12:15 class.
HW 01 due Friday at 3pm (link available soon). Submit as PDF to Google Classroom
(Rossman, Chance, Medina article is here)
Due Soon (next week?)
Read Modern Dive first few sections of Chapter 1 (Stop when it says: 1.2 How do I code in R?)
Download (or update) R on your computer
Download (or update) R-Studio on your computer
In Class:
Syllabus Topic: Late work policy
Intro to the Course (slides intentionally not included).
(5 min break)
Intro to Dophins Activity
01 -Lesson Notes.
How to reach Google Classroom (GC)
Syllabus Quiz (in groups) available on GC