How it works...

R has a built-in statistics function, which enables the user to perform descriptive statistics on a single variable. The recipe first introduces how to apply mean, sd, var, min, max, median, range, and quantile on a single variable. Moreover, in order to apply the statistics on all four numeric variables, one can use the sapply function. In order to determine the relationships between multiple variables, one can conduct correlation and covariance. Finally, the recipe shows how to determine the statistical differences of two given samples by performing a statistical test.