Answer:
It depends on how much the computer costs originally and the model of computer.
Explanation:
Say the computer costs 151.98 USD with the tax added, then the computer would cost 148.00 USD without tax. Or if the computer costs 162.79 USD with the tx added, then the computer would cost 160.00 USD without tax. It's the same for the rest but it also depends on the model of computer. (My calculations of adding 3 or 2 USD as the tax is just for example, i don't know how they calculate tax for computers)
151.98-148.00= 3.98$
162.79-160.00=2.79$