Suppose the Japanese yen exchange rate is $79=$ $$1,$ and the British pound exchange rate is $1=$ $$1\mathrm{.}58.$

a$.$

What is the cross$-$rate in terms of yen per pound? $($Round your answer to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ Suppose the cross$-$rate is $128=1.$ What is the arbitrage profit per dollar used? $($Do not round intermediate calculations and round your answer to $4$ decimal places, e$.$g$.,32\mathrm{.}1616.)$