1. STA220: Practice of Statistics 1 Section L0301: Health & Life Sciences September 17, 2013 1

2. Announcement TA office hours for this course start this week. They will be held in the Statistics Aid Centre: SS 1091. See Coursera for the schedule. 2

3. From last class … 3

4. 4 Your responses:

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6. 6 Topics this week: One variable statistics: five number summary, percentile, mean, trimmed mean, range, interquartile range (IQR), variance, standard deviation, z-score, frequency, relative frequency One variable plots and shape: histogram, dot plot, boxplot, pie chart, bar chart, distribution, skew, modes Types of variables: categorical, ordinal, quantitative Two categorical variables: contingency tables (cross-tabulations or two-way tables) including marginal, joint, and conditional distributions; side-by-side and stacked bar plots (stacked bar plots for conditional distributions are sometimes called segmented bar plots); independent Simpson's Paradox Features of data and statistics: observations, observational units (cases), variables, missing values, outliers, robust statistics, the empirical rule

7. 7 Today and Thursday: Muddiest point requests Topics not in videos A few problems

8. 8 Muddy points:

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16. 16 Muddy points:

17. 17 A quartile question:

18. 18 Muddy points:

19. 19 Shape of distribution

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21. 21 Percentiles Would you rather be in the 99 th percentile or the 1 st percentile of the class?

22. 22 The 99 th percentile is the value such that 99% of the data is less than it. What is another name for: The 25 th percentile? The 50 th percentile? The 75 th percentile?