Week 5

Normal & Poisson distributions; Variability in estimates & CI’s
Published

October 27, 2025

Modified

October 29, 2025

Overview of Week 5

Mon: Day 7

  • Normal distribution: Section 3.3
  • Poisson distribution: Section 3.4

Wed: Days 8 & 9

  • Day 8 topics: Variability in estimates: Section 4.1
  • Day 9 topics:
    • Confidence intervals for one mean (single-sample):
      • Sections 4.2 and 5.1.1, 5.1.2 (pgs. 238-242)
    • Student’s t-distribution
  • Days 7-9 Practice Problems
    • See new PP section below

Slides & Recordings

Day Topic Slides: html Slides: pdf Slides: web-page Slides with notes Recording Link Duration Code: qmd Code: html
Calculating probabilities in R
7 Normal dist and prob’s for standard normal (3.3.1, 3.3.3) Day 7: slides 1-5 Day 7 Part 1 27 min
7 Normal prob’s using z-scores (3.3.2, 3.3.4) Day 7: slides 6-7 same same Day 7 Part 2 15 min
7 Normal approx of binomial dist (3.3.6) Day 7: slides 8-9 same same Day 7 Part 3 14 min
7 Poisson dist (3.4) Day 7: slides 10-12 same same Day 7 Part 4 15 min
8 Variability in estimates: Section 4.1 Day 8: slides 1-13 Day 8 Part 1 26 min
8 4.1 con’td Day 8: slides 14-29 same same Day 8 Part 2 37 min same
8 R code demo Day 8 Part 3 11 min same
9 CI’s for 1 mean: 4.2 Day 9: slides 1-12 Day 9 Part 1 17 min
9 4.2 con’td Day 9: slides 13-19 same same Day 9 Part 2 17 min same same
9 4.2 con’td, 5.1.1, 5.1.2 (pgs. 238-242) Day 9: slides 20-23 same same Day 9 Part 3 14 min same same

Practice Problems

Day 7 PP

  • From Day 7 slides:
    • Example 3.3 parts (1) and (3) on pg 7 of slides
    • Example 3.8 parts (2) and (3) on pg 11 of slides

Day 8 & 9 PP

  • From Day 8 slides:
    • Slide 21: match figures to distribution (Sampling high schoolers’ weights)
    • Book exercise: 4.2
  • From Day 9 slides:
    • Slide 15: What percent CI was being simulated in this figure?
    • Slide 22: Calculate CI

Class discussion

During class you will be working in groups discussing the following:

Day 7

  • Practice Problems listed above
  • From (updated) HW 3:
    • Book exercises
      • 3.22, 3.32, 3.40

Day 8 & 9

  • Practice Problems listed above
  • From (updated) HW 3:
    • Day 8
      • R1: Youth weights Part 1 (YRBSS)
      • Non-book exercise: Ethan Allen
    • Day 9
      • Book exercises:
        • warm-up: 4.4, 4.6, 5.10
        • 5.6
      • R2: Youth weights Part 2 (YRBSS)

Homework

  • HW 3 v2 covers Days 6 - 9 and is due on Sat, 11/1
  • Make sure to check out the calculating probabilities in R code file: qmd, html
  • Note: the answer to exercise 3.31(b) in the textbook (not assigned) is incorrect.

Exam 2 information

  • Exam 2 will be on Wed, Nov. 5th
  • Samples of past exam questions and answers (on Sakai)
  • Material will cover Days 6-9,
    • which is approximately Sections 3.1-3.4, 4.1-4.2 from the textbook.
  • The exam will be in-class and handwritten. Bring a calculator.
  • You may bring one page of notes on an 8.5” x 11” sheet of paper.
    • You may use both sides.
    • You may type your notes.
    • You may not use screenshots of the notes or textbook
    • You will be turning in the page of notes with the exam, so please add your name to the sheet.