MATH1041 Lecture Notes - Lecture 2: Quartile, Interquartile Range, Linear Map
1 Aug 2018
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Document Summary
Wk1 lec 3 - 4 - numerical summaries. Types of numerical summaries - e. g proportion/percentages, mean/avg, median, To summarise one categorical variable: table of frequencies or percentages. To summarise one quantitative variable: means and sd. The mean is the average set of numbers in a data set, often represented by x bar . Physical interpretation as the centre of gravity of data. The mean can be heavily in uenced by outliers. The median is the middle value, represented by capital m . Boxplots - useful for describing shape of data. Handy for identifying outliers in your data - outliers are unusually large/small data points. Middle line represents median or q2 (2nd quartile) To create box plot for an odd number of data sets, to nd q1 and q3, we will exclude the median value. E. g if we have 13 values, median is n7, to nd q1, we consider n1 to n6 and q3, n8 to n13.
