xQuestion $4\mathrm{.}4.$ Although Walmart has the highest revenue in fortune$\_500,$ we can see that some other companies such as Apple have higher profit. This is because profit takes into account expenses such as operating costs and debts, whereas revenue does not take expenses into account. Compute the proportion of each company's revenue that ended up as profit. $($Your answer should be a Series.$)$

In$[91]$:

def profit$($x$,$y$)$:

return $($x$-$y$)/$x

profit$\_$proportion $=$ fortune$\_500.$loc$[[\text{'}$Revenue$\_$Dollars', 'Profit'$]]$

profit$\_$proportion