Consider the following hypotheses:

$H_0$:$220$

$H_A$:$<mn\; id="EditorElement\_3804874">2</mn><mn\; id="EditorElement\_3804875">2</mn><mn\; id="EditorElement\_3804876">0</mn>$

A sample of $72$ observations results in a sample mean of $209.$ The population standard deviation is known to be $18.($You may find it useful to reference the appropriate table: $z$ table or $t$ table$)$

a$-1.$ Calculate the value of the test statistic. $($Negative value should be indicated by a minus sign. Round final answer to $2$ decimal places.$)$