The upper bound is 875kg
The upper bound is the smallest value that would round up to the next estimated value.
For example, a mass of 70kg, rounded to the nearest 10kg, has a lower bound of 65kg, because 65kg is the smallest mass that rounds up to 70kg. The upper bound is 75kg, because 75kg is the smallest mass that would round up to 80kg (the next increment)
Because each parcel has a mass of 17kg correct to the nearest kg, the degree of accuracy is to the nearest 1kg
1kg/2=0.5kg
Upper bound for each parcel is 17.5kg
17.5x50