To determine the value that the contractor used for the weight of a person, we first need to find the total weight that the porch needs to support (3750 lb) and subtract the weight of the furniture (250 lb).
-
Subtract the weight of the furniture from the total weight:
-
Now, this weight (3500 lb) needs to be divided by the number of people (20) to find the weight per person:
Thus, the contractor used 175 lb as the weight of a person.