POLS 0825 Lecture Notes - Lecture 1: Standard Deviation, Standard Score, Histogram
Document Summary
*create a new variable that"s identical to the old variable without losing data. *new variable with a mathematical change to the old data. Use tabulate to display recoded variable in a table. *summarizes specific data in a table; useful to see min, max, # of obs. *label variable collegegrad is respondent a college graduate? . Mean (average of the sum of all observations divided by number of observations) Greatly affected by extreme outliers (creates inaccurate depiction of data) Take away one degree of freedom (n-1) to account for error in samples. Is sd 2 and vice versa, sd is the root of var(x) Used to calculate z-score for any given observation in a data set. Can be negative, positive (extremes) or close/exact to the mean (normal) Measure of how many standard deviations below (-) or above (+) the mean. A z-score of +1 is 1 standard deviation above the mean.