I need more info to answer this question
Prime cost is the combination of a manufactured product's costs of direct materials and direct labor. In other words, prime cost refers to the direct production costs.
Prime cost=direct material cost+direct labor cost
Direct material cost of a tabletop is
380×(1÷4)=95 for each tabletop
Direct labor cost
The question says The machinist cuts and polishes five tabletops each hour
Which means 27.50 of direct labor to cut and polish 5 tabletops So direct labor cost for each tabletop is
27.50÷5=5.5
Finally the prime cost of cutting and polishing a tabletop is
Prime cost=95+5.5=100.5
When your doing tax the tax is 9.25 you divide that by 100
the add that to your price then 12.5 divided by 100 and subtract that from what you ended up with so you should come out with a total of 4.22