An investigation is performed in which the concentration of nitrogen dioxide reacting is measured as a function of time.

$[$NO$2]($mol$/$L$)$

Time $($s$)$

$0\mathrm{.}500$

$0$

$0\mathrm{.}445$

$12$

$0\mathrm{.}380$

$30$

$0\mathrm{.}340$

$45$

$0\mathrm{.}250$

$90$

$0\mathrm{.}175$

$180$

a$)$ Plot a graph of $[$NO$]$ vs$.$ time

b$)$ Determine the average rate of reaction of NO$2$ between $10$ and $60$s

c$)$ As the $[$NO$2]$ halved, what was the effect on the instantaneous rate of reaction?