When a data set contains more than one variable, R offers another subsetting operator,

$, to access each variable individually. For the exercises below, we are interested only in the contents of one of the variables in the data set, called weight. We can access the weight variable by itself, using the $, with this expression: ChickWeight$weight. Run the following commands, say what the command does, report the output, and briefly explain each piece of output:

summary(ChickWeight$weight)

head(ChickWeight$weight)

mean(ChickWeight$weight)

myChkWts <- ChickWeight$weight quantile(myChkWts,0.50)