Answer:
340.67 kgm²/s
Step-by-step explanation:
R = Radius of merry-go-round = 1.9 m
I = Moment of inertia = 209 kgm²
= Initial angular velocity = 1.63 rad/s
m = Mass of person = 73 kg
v = Velocity = 4.8 m/s
Initial angular momentum is given by

The initial angular momentum of the merry-go-round is 340.67 kgm²/s