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STA220: Practice of Statistics 1
Section L0301: Health & Life Sciences
September 17, 2013
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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.
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From last class …
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Your responses:
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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
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Today and Thursday:
• Muddiest point requests
• Topics not in videos
• A few problems
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Muddy points:
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Muddy points:
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Muddy points:
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A quartile question:
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Muddy points:
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Shape of distribution
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PercentilesWould you rather be in the 99th percentile or the 1st percentile of the class?
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The 99th percentile is the value such that 99% of the data is less than it.
What is another name for:
• The 25th percentile?
• The 50th percentile?
• The 75th percentile?