A Task Involves Positioning Two Metal Parts with a Rubber

Essay

A task involves positioning two metal parts with a rubber gasket sandwiched between them, inserting two bolts into predrilled holes, threading a nut onto each bolt, and tightening each bolt with a pneumatic wrench. In a preliminary study, the manager observed one of his workers perform this task five times. The observations were made in an air-conditioned, well-lighted training facility, at ground level, with all tools and equipment clean and readily available.
$$\begin{array} { |l | l | l | l | l | l | } \hline \text { Observation: } & 1 & 2 & 3 & 4 & 5 \\\hline \text { Task time (seconds): } & 50 & 54 & 60 & 145 & 56 \\\hline\end{array}$$ a. What is the average observed time for this task?
b. What is the normal time for this task if the employee worked at a 10% slower pace than is typical for adequately trained workers?
c. What is standard time for this task if allowances are 7% constant and 5% variable?