from Chicago to Atlanta is 700 miles, so in plain-vanilla shipping costs for that will be $240 per every 100 lbs.
if we're shipping 2,000 lbs, hmmm that's 2000/100 = 20, so 100 lbs 20 times, so our plain-vanillla cost will be 20 * 240 = 4800 bucks.
Now, we're Da Bomb, and hell, why not, let's ship it on a 3-5 day, but that has a Premium of an extra 20%, hmmm that means our cost using 3-5 days service is 4800 + 20%.
[tex]\begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{20\% of 4800}}{\left( \cfrac{20}{100} \right)4800}\implies 960~\hfill \underset{final~cost}{\stackrel{4800~~ + ~~960}{5760}}[/tex]
