A methods and measurements analyst for Digital Devices needs to develop a time standard for the task of assembling a computer mouse. In a preliminary study, she observed one of her workers perform this task six times with the following results: $$\begin{array} { | l | c | c | c | c | c | c | }
\hline \text { Observation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Time(Seconds) } & 46 & 38 & 40 & 34 & 42 & 40 \
\hline
\end{array}$$ How many observations should be made if she wants to be 86.64 percent confident that the maximum error in the observed time is .5 second? Assume that the standard deviation of the task time is four seconds.
A) 10
B) 12
C) 120
D) 144
E) 169

Question

A methods and measurements analyst for Digital Devices needs to develop a time standard for the task of assembling a computer mouse. In a preliminary study, she observed one of her workers perform this task six times with the following results: $$\begin{array} { | l | c | c | c | c | c | c | } 
\hline \text { Observation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Time(Seconds) } & 46 & 38 & 40 & 34 & 42 & 40 \
\hline
\end{array}$$ How many observations should be made if she wants to be 86.64 percent confident that the maximum error in the observed time is .5 second? Assume that the standard deviation of the task time is four seconds.
A) 10
B) 12
C) 120
D) 144
E) 169

Quizplus · Accepted Answer

The Answer of A methods and measurements analyst for Digital Devices needs to develop a time standard for the task of assembling a computer mouse. In a preliminary study, she observed one of her workers perform this task six times with the following results: $$\begin{array} { | l | c | c | c | c | c | c | } 
\hline \text { Observation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Time(Seconds) } & 46 & 38 & 40 & 34 & 42 & 40 \
\hline
\end{array}$$ How many observations should be made if she wants to be 86.64 percent confident that the maximum error in the observed time is .5 second? Assume that the standard deviation of the task time is four seconds.
A) 10
B) 12
C) 120
D) 144
E) 169

A Methods and Measurements Analyst for Digital Devices Needs to Develop