$(40$ points$).$ Salida Industries sells its finished product for $$12$ per unit. Its fixed operating costs are $$15,000,$ and the variable operating cost per unit is $$5.$

Calculate the firm$$s earnings before interest and taxes $($EBIT$)$ for sales of $4,000$ units. $(8$ points$)$

Calculate the firm$$s EBIT for sales of $4,500$ units. $(8$ points$)$

Calculate the percentage changes in sales $($from the $4,000-$unit base level$)$ and associated percentage changes in EBIT for a shift in sales indicated in part $($b$).(10$ points$)$

Calculate the Degree of Operating Leverage $($DOL$).(6$ points$)$

On the basis of your findings in part $($d$),$ comment on the sensitivity of changes in EBIT in response to changes in sales. Support your statement with numbers. $(8$ points$)$