GlobalPetrol Corp, Exxon, and Shell want to borrow $$500,000.$ GlobalPetrol Copr and Shell require a variable rate loan to finance its business resources while Exxon requires a fixed rate to meet its finance obligation rate. GlobalPetrol Copr, Exxon, and Shell have $5-$year, $5-$year, and $4-$year of time horizons respectively. Somatsu Investment offers to swap their interest rates while offering an arbitrage opportunity to exploit their comparative advantage

Table: $1$ Firms Interest Rates and Time Horizon

Fixed Floating Cash Flow Time Horizon

GlobalPetrol Corp $4\%$ L$-0\mathrm{.}1\%$ $$500,0005$

Exxon $5\mathrm{.}2\%$ L$+0\mathrm{.}6\%$ $$500,0005$

Shell $5\mathrm{.}2\%$ L$+0\mathrm{.}6\%$ $$500,0004$

Compute the net borrowing costs by designing a Vanilla interest rate swap for the correct parties in which Somatsu Investment acts as an intermediary, taking $0\mathrm{.}1\%$ as a fee and the higher$-$rated firm will share $70\%$ of the swap benefit. $($Refer Table $1)$