Given data:
The initial velocity of the robber towards the north is 133.0 mi/h.
The final velocity of the robber towards the north is 101.0 mi/h.
The starting time of the robber is 3:00 PM.
The final time of the robber is 3:37 PM.
Solution:
The time taken by the robber in the given ride is,

Thus, the average acceleration of the robber is,

where v is the final velocity and u is the initial velocity,
Substituting the known values,

Here, the negative sign indicates the direction of acceleration is towards the south.
Hence, the average acceleration of the robber is -51.61 miles per hour squared.