ECON 2B03 Lecture Notes - Lecture 4: Order Statistic, Frequency Distribution, Summary Statistics
25 Apr 2016
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Designated by greek letters (e. g. , u (mu), o (sigma) Designated by roman letters (e. g. , x (sample mean), s (standard deviation) Different values indicated by subscripts 1,2,3, etc. (e. g. x1, x2, x3, ) Sample total = n (the number of pieces of data in your sample) In statistics, we often need to "accumulate" or "sum" some variable of interest (e. g. 100 +34 +16. For example, a might denote, say,, income, with a1 being the income of the first person in our sample. It is supremely convenient to avoid having to write things like: A1 +a2+a3+a4+a5+a6, or (a1-b) + (a2-b) +(a3-b)+(a4-b), or even (a1-b)^2 + (a2-b)^2+(a3- One convenient operator that we shall use heavily is the "summation" operator. In r we use the sum () function. Focus on the spread of data around a set"s center. Describe the symmetry (or asymmetry) of a frequency / density curve, as well as how flat or peaked it is.
