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03/05/2003 Week #2 江支弘
Chapter Two
Describing, Displaying, and Exploring Statistical Data
03/05/2003 Week #2 江支弘
03/05/2003 Week #2 江支弘
Displaying Data 展示數據
First step in data analysis電子試算表與統計圖表Overall pattern 整體型態 /趨勢 v.s. Exception
sFrom graph to numerical description
03/05/2003 Week #2 江支弘
03/05/2003 Week #2 江支弘
Scatter plot
03/05/2003 Week #2 江支弘
Box plot
03/05/2003 Week #2 江支弘
Displaying Distributions 呈現分佈
Distribution of a variable: what values the variable takes and how often each value occurs
Histogram 直方圖Ex8: percent of age 65 or older, by state, p1
50中文
03/05/2003 Week #2 江支弘
03/05/2003 Week #2 江支弘
How to make a histogram 直方圖的製作
(Ex8) Step 1 數據分組 : divide the range of the data into classes of equal width
Step 2 分組統計次數 : count the # of observations in each class
03/05/2003 Week #2 江支弘
Step 3: Draw the histogram
03/05/2003 Week #2 江支弘
Interpreting histograms
與長條圖不同 : base scale; width of bar; Pattern and deviations 型態與偏差Outlier 離群值 : an individual observation that f
alls outside the overall patternOverall pattern of a distribution 分佈的一般型態
Center and Spread 中心與離度
Shape (e.g. symmetric)
03/05/2003 Week #2 江支弘
Symmetric and Skewed distributions對稱分佈與偏斜分佈
A distribution is
Symmetric if the right and left side of the histogram are approx. mirror images of each other
Skewed to the right if the right side of the histogram (upper half) extends much farther out than the left side
03/05/2003 Week #2 江支弘
03/05/2003 Week #2 江支弘
Normal distribution
03/05/2003 Week #2 江支弘
Exponential distribution
03/05/2003 Week #2 江支弘
Uniform distribution
03/05/2003 Week #2 江支弘
Skewed distribution