Suppose that the spot USD$/$GBP is $1\mathrm{.}45701\mathrm{.}4576$ and the six$-$month forward USD$/$GBP is $1\mathrm{.}44081\mathrm{.}4434.$ Compute the annualized forward discount or premium on GBP relative to USD.

My answer is:

a$)$ Mid$-$rate for spot: $1\mathrm{.}4573,$ Mid$-$rate for forward: $1\mathrm{.}4421$

Annualized forward discount $=\{(1\mathrm{.}4421-1\mathrm{.}4573)/(1\mathrm{.}4573)\}$ x $(360/180)$ x $100$

$=-2\mathrm{.}0861\%$

b$)$ Annualized forward discount $=\{(1\mathrm{.}4408-1\mathrm{.}4570)/(1\mathrm{.}4570)\}$ x $(360/180)$ x $100$

$=-2\mathrm{.}2237\%$

I don't know which one is right, please let me know with thorough explanation. Thank you!