$.$ Assuming the data in the following table for corporate bonds, compute the theoretical hedge ratio at the average spread level for the three credit ratings $($X$,$ Y$,$ and Z$)$: Aaa$-$Aa A Baa Volatility of changes in Treasury yields $(\%/$day$)0\mathrm{.}0740\mathrm{.}0740\mathrm{.}074$ Volatility of relative spread changes $(\%/$day$)2\mathrm{.}802\mathrm{.}001\mathrm{.}80$ Correlation between changes in yields and spreads $0\mathrm{.}200\mathrm{.}270\mathrm{.}32$ Average spread $(\%)1\mathrm{.}151\mathrm{.}702\mathrm{.}30$ Theoretical hedge ratio at average spread level X Y Z MLA $9$th Edition $($Modern Language Assoc.$)$ Frank J$.$ Fabozzi, and Francesco A$.$ Fabozzi. Bond Markets, Analysis, and Strategies, Tenth Edition. The MIT Press, $2021.$ APA $7$th Edition $($American Psychological Assoc.$)$ Frank J$.$ Fabozzi, & Francesco A$.$ Fabozzi. $(2021).$ Bond Markets, Analysis, and Strategies, Tenth Edition. The MIT Press.