Q$3.$ A $200$ points job $($i$.$e$.$ grade $8$ employee$)$ is assigned an average rate of $\backslash (4\backslash$$ $\backslash )$ while a $285$ points job $($i$.$e$.$ grade $5$ employee$)$ earns $\backslash (6\mathrm{.}5\backslash$$ $\backslash )$ rate in average. If the administration opts for a linear trend line job evaluation, what would be the approximate interval of wages area for a grade $3$ employee? $(10$ pts $)$