The masses to the nearest 0.5 kg of two parcels are 1.5 kg and 2.5 kg. calculate the lower and upper bounds of their combined mass.

(3.5, 4.5)

Step-by-step explanation:

The masses have a total margin of 0.5 kg, or ±0.25 kg.

The mass of the first parcel is 1.5 kg ± 0.25 kg.

The mass of the second parcel is 2.5 kg ± 0.25 kg.

The combined mass is:

(1.5 kg + 2.5 kg) ± (0.25 kg + 0.25 kg)

4 kg ± 0.5 kg

So the lower bound is 3.5 kg and the upper bound is 4.5 kg.