Final answer:
To estimate the number of sets of crutches used by the hospital, subtract the number of sets remaining at the end of the month from the number of sets at the beginning of the month.
Step-by-step explanation:
To estimate the number of sets of crutches the hospital used in the last month, we need to calculate the difference between the number of sets at the beginning and the number of sets remaining at the end of the month.
Amount used = Beginning amount - Remaining amount
Amount used = 392 sets - 37 sets = 355 sets
Therefore, the hospital used approximately 355 sets of crutches in the last month.