can anyone explain this with steps?

Weldex Industries begins to manufacture a newly designed, small, spot welding machine. The labour hours required for making the second and third units are 29.3 and 28.3 hours respectively. The labour hours required to manufacture the first unit are close to Select one: O 27.6 hours 32.2 hours 30.0 hours 31.1 hours Based on question 4, the labour hours required to manufacture the 50 unit are close to Select one: O 19.8 hours O 23.0 hours 22.2 hours 21.5 hours If labour costs are $18/hour, the total labour costs to produce the first four machines are close to Select one: O $2058 O $2093 O $1975 O$2057