BIOL 3312 Lecture 2: Lecture 2 Measures of Data
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Lies between upper and lower half of set. Only one that can be used for ordinal data. For odd number of n find median position by (n+1)/2. For even number find middle number and middle number +1 -> average those 2 c. Any type of data: discrete/continuous and all n-o-i-r. Only one that can be used for nominal data. Take the same categories as in frequency table and corresponding frequencies. Difference between highest and lowest value sensitive to outliers depends on sample size --> more data=larger range c. Interquartile range i. ii. iii. find 4 quartiles, find median and then median of lower and upper halves upper quartile - lower quartile (75%-25%) outliers can be excluded d. Distance of each data point from the mean averaged. Take absolute value of each deviation otherwise the average deviation will be 0 e. Squares are not liked in calculus because they provide cusps where derivatives do not exist f.
