BUSI 1450U Chapter Notes - Chapter 5: Average Absolute Deviation, Standard Deviation, Unit
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Measures of spread: measure of spread a single number that describes the degree of variety among the values of a distribution. Also called measures of variation or measures of dispersion. Range: range = largest value smallest value, pro: easy to calculate and understand, con: tells us nothing about the actual distribution of the data set, con: highly affected by outliers, range cannot be used with nominal-level data. Variance and standard deviation of a population: variance is a good measure of variation, but has one issue: the unit of variance is not the same as the unit of data values. Variance for a sample: same as for a population. Excel: standard deviation and range: population: =stdevp(highlight the cells, sample: =stdev(highlight the cells, range: =max(highlight cells)-min(highlight the cells) Minitab: standard deviation, sample and range for a sample: stat / basic statistics / display descriptive statistics, select the variable / statistics / select standard deviation, variance, range / ok.