Antenna Gain - Gain Comaprison(Transfer) Method

Evening Gents,

Please see the first .pdf as my work will be referring to questions 1) through 4).

Attached in the second .pdf is my attempt at the solution.

My calculated gains from part 1) don't seem to be lining up with the gains from part 4).

Am I correct to use the power values in Watts and not dB in part 1)?

Is the approximate formula in 4) meant for HPBW values given in radians?

EDIT: I've also quickly made an attempt at part 5) a) and b),

For part 5) a), I'm not sure how exactly to link the relationship between V1 and V2, but for part 5 b) I've got,

\(Z_{c1} = \sqrt{50 \Omega * 200 \Omega} = 100 \Omega\)

\(Z_{c2} = \sqrt{50 \Omega * 150 \Omega} = 50\sqrt{3} \Omega\)

Can someone give me a push in the right direction for Part 5) a)?

Thanks again!

Thanks again!