At a New Watch Assembly Plant,a Job Is Divided into Three

Multiple Choice

At a new watch assembly plant,a job is divided into three work elements.The element times for the first four cycles are recorded by the continuous method and are presented below along with a performance rating factor (RF) for each element.
$$\begin{array} {r } { \text { Observation (time in min) } } \quad \quad \\\begin{array} { | c | c | c | c | c | c | } \hline \text { Work Element } & 1 & 2 & 3 & 4 & \mathrm { RF } \\\hline 1 & 0.50 & 2.32 & 4.22 & 6.16 & 1.0 \\\hline 2 & 1.45 & 3.24 & 5.20 & 7.06 & 1.1 \\\hline 3 & 1.87 & 3.62 & 5.61 & 7.49 & 0.9 \\\hline\end{array}\end{array}$$
The standard time for this job,assuming that the allowance is 18 percent,is

A) fewer than or equal to 1.9 minutes.
B) greater than 1.9 minutes but fewer than or equal to 2.0 minutes.
C) greater than 2.0 minutes but fewer than or equal to 2.1 minutes.
D) greater than 2.1 minutes.