Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Fall 2016 Room 150 Harvill Building 10:00 - 10:50 Mondays, Wednesdays & Fridays. Welcome http://www.youtube.com/watch?v=oSQJP40PcGI
By the end of lecture today 9/19/16 Use this as your study guide By the end of lecture today 9/19/16 Characteristics of a distribution Central Tendency Dispersion Measures of variability Range Standard deviation Variance Memorizing the four definitional formulae
Schedule of readings Before next exam (September 23rd) Friday: University ID 4-digit class ID 2 pencils 2 calculators Seating Chart Study guide Schedule of readings Before next exam (September 23rd) Please read chapters 1 - 5 in OpenStax textbook Please read Appendix D, E & F online On syllabus this is referred to as online readings 1, 2 & 3 Please read Chapters 1, 5, 6 and 13 in Plous Chapter 1: Selective Perception Chapter 5: Plasticity Chapter 6: Effects of Question Wording and Framing Chapter 13: Anchoring and Adjustment
Labs continue this week Lab sessions Labs continue this week Everyone will want to be enrolled in one of the lab sessions
Labs continue this week Lab sessions Labs continue this week Everyone will want to be enrolled in one of the lab sessions
Summary of 7 facts to memorize
Homework Assignments 7 & 8 Please complete the homework worksheets Calculating Descriptive Statistics And Presenting Findings in a Memorandum Due: Today
Review of Homework Worksheet Each of these are deviation scores 3 – 5 = -2 -22= 4 6 – 5 = +1 -2 1 3 -1 4 1 9 12= 1 3 -3 -1 1 9 1 Σ(x - µ) = 0 50 36 36 2 = 2 10 - 1 This is the standard deviation! 5 4 4.5 2 8 6
Review of Homework Worksheet -12= 1 5 – 6 = -1 -1 2 3 1 4 9 22= 4 8 – 6 = +2 -1 3 1 -5 1 9 25 60 52 52 2.4 = 2.4 10 - 1 5 6 5.5 1 9 8
Summary of 7 facts to memorize
Price per Movie Package Movie Packages We sampled 100 movie theaters (Two tickets, large popcorn and 2 drinks) What is the most common “deviation score”? 12 Deviation = 0 10 Frequency 8 6 4 2 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 Price per Movie Package This distance is about 3 - 4 points on number line What’s the ‘typical’ or standard deviation? Mean = $37 Range = $27 - $47 Standard Deviation = 3.5
Amount of Bonuses (based on commission) We sampled 100 retail workers 68% 95% 99.7% What’s the ‘typical’ or standard deviation? This distance is about 10 points on number line What’s the largest possible deviations? Mean = $50 Range = $25 - $75 $75 – $50= $25 $25 – $50= -$25 Standard Deviation = 10
Pounds of pressure to break casing on an insulator (We applied pressure until the insulator casing broke) What’s the ‘typical’ or standard deviation? This distance is about 200 points on number line Mean = 1700 pounds Range = 1200 – 2100 What’s the largest possible deviation? 2100-1700 = 400 Standard Deviation = 200 1200-1700 = -500
What’s the ‘typical’ or standard deviation? Waiting time for service at bank We sampled 100 banks (From time entering line to time reaching teller) What’s the ‘typical’ or standard deviation? This distance is about .2 -.3 points on number line Mean = 3 minutes Range = 2.4 - 3.8 What’s the largest possible deviation? 3.8-3.0=.8 2.4 -3.0=-.6 Standard Deviation = 0.30
Quiz: Just for fun Monthly electric bills for 50 apartments (amount of dollars charged for the month) Mean = $150 Range = 95 - 205 The best estimate of the population standard deviation is a. $150 b. $25 c. $50 d. $63 Standard Deviation = 25
You already know this by heart 1 sd above and below mean 68% 2 sd above and below mean 95% 3 sd above and below mean 99.7% 68% Confidence interval 95% Confidence interval 99% Confidence interval You already know this by heart
Thank you! See you next time!!