determine Q whenT=73.16

Given T=47.4é^0.31Q (It is e raised to 0.31Q where Q=Theta

so you are solving

73.16 = 47.4 e.31ß ? (I used ß instead of theta)

divide both sides by 47.4

1.543 = e.31ß ln both sides

ln1.543 = .31ß lne
ß = ln1.543 /.31 (remember lne = 1)

so your Q = 1.40

check:
47.4(e^(.31*1.40)
= 47.4(1.5134)
= 73.158