Answer:
the increase in the labor productivity is 25%
Step-by-step explanation:
The computation of the increase in the labor productivity is shown below
= Different in valves per shift ÷ currently production valves per unit
= (2,000 valves - 1,600 valves) ÷ 1,600 valves
= 400 valves ÷ 1,600 valves
= 25%
Hence, the increase in the labor productivity is 25%