Answer:
Moment of inertia,

Step-by-step explanation:
It is given that,
Mass of the monkey, m = 1.8 kg
Distance from the center of mass, d = 0.25 m
The time period of oscillation, t = 0.94 s
It is assumed to find the moment of inertia of the wrench about an axis through the pivot. the time period of the oscillation is given by :




So, the moment of inertia of the wrench about an axis through the pivot is
. Hence, this is the required solution.