ABSTRACT
Most data analyses describe or summarize the sample data with various statistics such as the mean and standard deviation. Also introduced in this chapter are the related statistics of skewness and kurtosis, plus order statistics such as the median and the interquartile range. Many of these statistics are produced from lessR data visualization functions but more generally compute with the lessR function pivot(). Compute one or more descriptive statistics from a single call to pivot(), and do data aggregation across groups defined by one or more categorical variables. For the statistics of primary interest, estimate the value in the population as a whole with inferential statistics, illustrated in this chapter for the mean according to the one sample t-test obtained with the lessR function ttest(). Descriptive and inferential statistics are discussed for a special instance of the mean, the proportion, the mean of binary data scored 0 and 1. Use the lessR function Prop_test() for the descriptive and inferential analysis of the proportion.
