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Introduction to Statistics for the Social Sciences SBS200, COMM200, GEOG200, PA200, POL200, or SOC200 Lecture Section 001, Spring, 2014 Room 120 Integrated Learning Center (ILC) 10:00 - 10:50 Mondays, Wednesdays & Fridays . Welcome. http://www.youtube.com/watch?v=oSQJP40PcGI. Please click in.
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Introduction to Statistics for the Social SciencesSBS200, COMM200, GEOG200, PA200, POL200, or SOC200Lecture Section 001, Spring, 2014Room 120 Integrated Learning Center (ILC)10:00 - 10:50 Mondays, Wednesdays & Fridays. Welcome http://www.youtube.com/watch?v=oSQJP40PcGI
Please click in My last name starts with a letter somewhere between A. A – D B. E – L C. M – R D. S – Z
Use this as your study guide By the end of lecture today2/12/14 • Measures of variability • Estimating standard deviation • Review for Exam 1
Schedule of readings Study Guide is online Before next exam (February 14th) Please read chapters 1 - 4 in Ha & Ha textbook Please read Appendix D, E & F onlineOn 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
Exam 1 – This Friday February 14th Study guide is online Bring 2 calculators (remember only simple calculators,we can’t use calculators with programming functions) Bring 2 pencils (with good erasers) Bring ID
Lab sessions Labs continue this week
No Homework Just study for exam
“Sum of Squares” “Sum of Squares” “Sum of Squares” “Sum of Squares” Deviation scores Standard deviation: The average amount by which observations deviate on either side of their mean Diallo is 0” Preston is 2” Mike is -4” Hunter is -2 Shea is 4 David 0” Remember, it’s relative to the mean “n-1” is “Degrees of Freedom” “n-1” is “Degrees of Freedom” Generally, (on average) how far away is each score from the mean? Based on difference from the mean Mean Remember, We are thinking in terms of “deviations” Diallo Please memorize these Preston Shea Mike
Review of Homework Worksheet 3 – 5 = -2 -22= 4 6 – 5 = +1 -2 1 3 -1 0 4 1 9 1 0 12= 1 3 -3 -1 1 -1 9 9 1 1 1 50 0 36 36 2 = 2 10 - 1 Mode = 4 5 4.5 6 2 8
Review of Homework Worksheet -12= 1 5 – 6 = -1 -1 2 -1 -1 3 1 4 1 1 9 22= 4 8 – 6 = +2 0 -1 3 1 -5 0 1 9 1 25 60 0 52 52 2.4 = 2.4 10 - 1 Mode = 5 6 5.5 8 1 9
Review of Homework Worksheet Must be complete and must be stapled
Let’s estimate some standard deviation values Standard deviation is a ‘spread’ score We’re estimating the typical distance score (distance of each score from the mean)
Raw scores, z scores & probabilities Please note spatially where 1 standard deviation falls on the curve
Raw scores, z scores & probabilities Please note spatially where 1 standard deviation falls on the curve 68% 99.7% 95%
2 sd above and below mean 95% 1 sd above and below mean 68% 3 sd above and below mean 99.7% These would be helpful to know by heart – please memorize areas
Raw scores, z scores & probabilities 1 sd above and below mean 68% z = +1 z = -1 Mean = 50 S = 10 (Note S = standard deviation) If we go up one standard deviation z score = +1.0 and raw score = 60 If we go down one standard deviation z score = -1.0 and raw score = 40
Raw scores, z scores & probabilities 2 sd above and below mean 95% z = -2 z = +2 Mean = 50 S = 10 (Note S = standard deviation) If we go up two standard deviations z score = +2.0 and raw score = 70 If we go down two standard deviations z score = -2.0 and raw score = 30
Raw scores, z scores & probabilities 3 sd above and below mean 99.7% z = +3 z = -3 Mean = 50 S = 10 (Note S = standard deviation) If we go up three standard deviations z score = +3.0 and raw score = 80 If we go down three standard deviations z score = -3.0 and raw score = 20
Movie Packages We sampled 100 movie theaters(Two tickets, large popcorn and 2 drinks) 12 10 Frequency 8 6 4 2 0 • 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 • Price per Movie Package 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% $75 – $50= $25 What’s the largest possible deviation? $25 – $50= -$25 Mean = $50 Range = $25 - $75 What’s the ‘typical’ or standard deviation? Standard Deviation = 10
Thank you! See you next time!!