Problem $1\mathrm{.}11-4.$

Note: In $($a$),$ use both of the following methods:

i$)$ by hand with a calculator $-$ show formula with data plugged in$.$

ii$)$ by $R$ computing below $-$ provide your $R$ codes and output. $($Open $R,$ in $R$ Console window,

type in or copy$/$paste each R command below behind a prompt $">"$ and click return to obtain

results. Lines start with $"$#$"$ are descriptions or comments.$)$

# Manually input the data and name the object "age":

$>$ age $=c(13\mathrm{.}6,13\mathrm{.}9,14\mathrm{.}0,14\mathrm{.}2,14\mathrm{.}9,15\mathrm{.}0,15\mathrm{.}0,15\mathrm{.}1,15\mathrm{.}4,16\mathrm{.}4)$

# See the data:

$>$ age

# compute mean, var, sd$,$ median:

$>$ mean $($age$)$

age